Contentm.myjizhi.com/files/20181112-abs-cn.pdf · 2018-11-29 · Quantum Dot embedded in Polymer Film Wei-Jie Guo, Nan Chen, Yue Lin, Ting-Zhu Wu, Hao-Chung Kuo, ... micro-LED display,

第十五届中国国际半导体照明论坛暨 2018 国际第三代半导体论坛

2018 年 10 月 23-25 日中国·深圳

15th China International Forum on Solid State Lighting & 2018 International Forum on Wide Bandgap Semiconductors China

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Content

SW101-Plenary: Opening Ceremony & Plenary Forum-------------------------------------------------

S201-Technologies for LED Chip, Packaging and Modules--------------------------------------------

S202- Driver and Intelligent Control Technology--------------------------------------------------------

S203- LED Lighting in Bio-Agriculture-------------------------------------------------------------------

S204- Light Quality and Lighting for Health--------------------------------------------------------------

S205-Solid-State Ultraviolet Device Technology--------------------------------------------------------

W201-Technologies for SiC Materials and Devices-----------------------------------------------------

W202- Technologies for GaN Materials and Devices---------------------------------------------------

W203- RF Technology based on Wide Bandgap Semiconductors-------------------------------------

W204-Power Devices Packaging and Application-------------------------------------------------------

W205- Ultra-Wide Bandgap Semiconductor Technology-----------------------------------------------

S206/W206-Semiconductor Equipment Technologies and Intelligent Manufacturing--------------

S207/W207-Technologies for Reliability and Thermal Management----------------------------------

S208/W208-Technologies for Micro-LED and Novel Display------------------------------------------

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2018 年 10 月 23-25 日中国·深圳


1

SW101-201810141953

Silicon Carbide power devices: fabrication and path to commercialization

Victor Veliadis *Deputy Director and Chief Technology Officer, PowerAmerica US Manufacturing Institute

Deptartment of Electrical and Computer Engineering, North Carolina State University

North Carolina State University, Raleigh, NC, USA

[email protected]

Abstract

In an increasingly electrified technology driven world, power electronics is central to the entire manufacturing economy.

Silicon (Si) power devices have dominated power electronics due to their low cost volume production, excellent starting

material quality, ease of processing, and proven reliability. Although Si power devices continue to make significant

progress, they are approaching their operational limits primarily due to their relatively low bandgap and critical electric

field that result in high conduction and switching losses, and poor high temperature performance. In this presentation, the

favorable material properties of Silicon Carbide (SiC), which allow for highly efficient power devices with reduced form

factor and relaxed cooling requirements, will be highlighted. Foundry considerations and cost reduction strategies will be

outlined elucidating the path to the projected $1B SiC device market by 2022. Design considerations of SiC MOSFETs,

currently being inserted in the majority of SiC based power electronic systems, will be presented. Fabrication will be

discussed with an emphasis on the processes that do not carry over from the mature Si manufacturing world and are thus

specific to SiC devices. Finally, common SiC Edge Termination techniques, which allow SiC devices to reach their full

high-voltage potential, and their impact on device performance will be summarized.


2018 年 10 月 23-25 日中国·深圳


2

S201-201810181004

AlGaN nanowire UV LED using graphene as substrate and transparent electrode

Helge Weman1,2

¹ Department of Electronic Systems, Norwegian University of Science and Technology (NTNU),

NO-7491, Trondheim, Norway.

² CrayoNano AS, Sluppenvegen 6, NO-7037, Trondheim, Norway.

Abstract

In 2012 we described a generic atomic model, which describes the epitaxial growth of semiconductors on graphene that is

applicable to all conventional semiconductor materials.1 The epitaxial growth of semiconductors on graphene is very appealing

for device applications since graphene can function not only as a replacement of the semiconductor substrate but in addition as a

transparent and flexible electrode for e.g. solar cells and LEDs.

For deep ultraviolet AlGaN-based light emitting diodes (LEDs), in need for various disinfection and sterilization purposes, the

concept offers a real advantage over present thin film-based technology. Deep UV LEDs are today very expensive and

inefficient due to the lack of a good transparent electrode (ITO is absorbing in deep UV), the high dislocation density in the

active thin film layers, low light extraction efficiency, and the use of very expensive AlN substrates or AlN buffer layers on

sapphire substrates. CrayoNano are developing UV LEDs based on AlGaN nanostructures on graphene substrates, which

potentially can overcome these problems. A first proof-of principle flip-chip GaN/AlGaN nanowire UV LED using graphene as

both substrate and transparent electrode has recently been made. Electroluminescence measurements show a distinct GaN

bandgap related emission peak at 365 nm at room temperature with no defect-related yellow emission.

1 A.M. Munshi, et al., Nano Lett. 12, 4570 (2012).


2018 年 10 月 23-25 日中国·深圳


3

S201-201809280938

Pyramid-type flexible gallium nitride based LED fabricated by laser ablation and dual substrate

transfer technology

Feng Yun, Zhenhuan Tian, Yufeng Li, et al

Solid State Lighting Engineering Research Center, School of Electronic and Informational Engineering, Xi’an Jiaotong

University, Xi’an, Shaanxi, China

Abstract

We used laser drilling to make a patterned substrate. By precisely controlling the laser processing parameters and changing the

diameter, depth and spacing of the ablation holes, a patterned sapphire substrate with a regular bowl-like structure is obtained.

We analyzed the morphology, spectral distribution, crystal quality, optical and mechanical properties of the pyramidal

micro-LEDs grown on this substrate. The pyramid array is transferred from the sapphire substrate to the flexible substrate using

laser lift-off and dual substrate transfer process. Through the reasonable control of the curing parameters of the temporary

substrate, a complete large-scale micro-LEDs transfer is realized, and a transparent electrode is fabricated. The micro-LED

arrays with various morphologies were successfully fabricated, and their morphology, spectral distribution and crystal quality

were characterized. Finally, we studied the effects of pyramid structure on the mechanical properties and failure mode of the

device through comparison between simulation and experiment.


2018 年 10 月 23-25 日中国·深圳


4

S201-201807201055

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Research on Degradation of MAPbBr3 Quantum Dot embedded in Polymer Film

Wei-Jie Guo, Nan Chen, Yue Lin, Ting-Zhu Wu, Hao-Chung Kuo, Yi-Jun Lu, Zhong Chen

Xiamen University

Room 328, Physics Hall, Haiyun Campus, Xiamen University, Xiamen, Fujian, China

[email protected]

Abstract

The quantum dot (QDs) is regarded as the next generation optical materials as it possesses narrow line-width spectra, highly

tunable color, and high quantum yields. For the down-converting phosphorus material of full-spectra white light LED and

micro-LED display, the QD can significantly enhance the quality of devices, being a competent candidate for general lighting

and display. Among various types of QDs, perovskites attract great attention recently. Its emission wavelength can be tuned

continuously by adjusting the ratio of halogens, being superior to those conventional QDs, for which one needs to modify the

grain sizes. However, the stability remains an obstacle yet to be overcome, especially for those in the application of while-LED

or micro-LED, where extreme temperature and light intensity coexist at the same time.

In this work, we synthesize MAPbBr3 perovskite quantum dot that embedded in polymer. The average size of QDs is as small

as 3 nm in diameter. Through studying the aging behaviors under different environments with various atmospheres, luminance

intensity, and humidity, we investigate the luminesces quenching of MAPbBr3. The work provides a mechanism for perovskite

degradation, which points a possible direction to realization of highly stable perovskite QDs.


2018 年 10 月 23-25 日中国·深圳


5

S201-201807201954

850 nm Infrared Light-emitting Diodes Composed of AlGaAs Current Spreading Layers Grown by

Multi-step Variable Growth Rate Method

Kaixuan Chen

Xiamen Changelight Co., Ltd.

No.259-269, Xiang Tian Road, Xiamen Torch (Xiang An) Industrial Park

Email: [email protected]

Abstract

Infrared Light-emitting Diodes (IR LEDs) have been widely used in applications such as remote controllers, surveillance

cameras, IR detectors and datacom devices. In recent years, IR LEDs are also being used in emerging applications, such as IR

touch panels, eye tracking devices, automotive night-vision systems, etc. [1-4] Traditionally, IR LEDs are mainly grown by

Liquid Phase Epitaxy (LPE). The advantages of LPE include simple hardware configurations, fast growth rates, non-toxic

byproducts, etc. However, it is quite difficult to precisely control the epi-layer thickness or the doping uniformity by using LPE.

Furthermore, it is unable to grow complicated multiple quantum well (MQW) structures with smooth surface morphologies by

LPE. Therefore IR LEDs grown by LPE are mostly used in lower-power applications. On the contrary, metal organic chemical

vapor deposition (MOCVD) is being used to grow complicated while smooth MQW structures on large diameter substrates. The

chemical composition, layer thickness, doping concentration and interface quality can be precisely controlled by MOCVD.

Therefore IR LEDs grown by MOCVD are being used in mid-power and high-power applications.

The vertical-thin-film (VTF) structure is widely used in IR LEDs grown by MOCVD for mid-power and high-power

applications. During the fabrication process of the VTF structure, the GaAs substrate is removed after bonding the epi-layer to a

Si substrate. In order to separate the epi-layer and the GaAs substrate by chemical etching, an etch-stopping layer composed of

phosphorous compounds is inserted between the GaAs buffer layer and the AlGaAs current spreading layer. The surface

morphology of the AlGaAs current spreading layer grown on top of the etch-stopping layer affects the crystalline quality of the

following functional layers, such as confinement layers and MQWs, which determine the quantum efficiency and the lifetime of

the IR LEDs. [5] In this paper, 850 nm IR LEDs composed of AlGaAs current spreading layers grown by multi-step variable growth rate

method are investigated. It is found that the multi-step variable growth rate method can improve the surface morphology and the

crystalline quality of the n-type Al0.25Ga0.75As current spreading layer and the epi-layers on top of it. Thus the leakage current

and the series resistance of the 850 nm IR LEDs can be reduced. Furthermore, the generation of the non-radiative recombination

centers within the MQW active region can be reduced by using the multi-step variable growth rate method to grow the n-type

Al0.25Ga0.75As current spreading layer. Thus the light output power and the lifetime of the 850 nm IR LEDs can be increased.

References

1. Hiroyuki K. et al., “Development of Super High Brightness Infrared LEDs”, SEI Technical Review, Number 72, (2011),

pp. 86-89.

2. Illek S. et al., “High Power LEDs for Visibal and Infrared Emission”, Proceeding of SPIE, Vol. 6134, (2006), pp.

613401-1 – 614401-9.

3. Bockstaele R. et al., “Realisation of Highly Efficient 850nm Top Emitting Resonant Cavity Light Emitting Diodes”,

Electronics Letters, Vol. 35, (1999), pp. 1564-1565.

4. Windisch R. et al., “31% Absolute External Quantum Efficiency 850-nm LEDs and Their Modulation Behavior”, IEDM 98,

San Francisco, CA, 1998, pp.1026-1028.

5. Schubert E. F., Light-Emitting Diodes, Cambridge University Press (New York, 2006), pp. 127-132.

Figure 1: N-type Al0.25Ga0.75As current spreading layers grown by (a) the constant growth rate method and (b) the variable growth rate method


2018 年 10 月 23-25 日中国·深圳


6

S201-201807222024

Optimized Self-Adaptive Phosphor Coating Structure of White Light Emitting Diodes By Double

Conformal Coating Technology

Weibing Zheng, Haibo Rao, Ting Li, Qinghao Meng, Jun Peng and Zhiqi Wu

University of Electronic Science and Technology of China

No.4 Block 2 N.Jianshe Road Chengdu, SiChuan, China

[email protected]

Abstract

Since the pc-WLEDs appeared, its coating structure has abstracted attention of many researchers, as phosphor coating structure

is one of the most important factors in lighting quality of pc-WLEDs. Many coating structures have been proposed with the

efforts of the researchers, which including conventional phosphor coating, conformal phosphor coating etc. However, the

disadvantages of each coating technology hinder them apply to a wider field. In this experiment, we use double conformal

coating to optimize phosphor coating structure by employing self-exposure technique. The results of this experiment shows that

this new coating structure improves the homogeneity of yellow blue photon ratio(Y/B) and the angle-dependent correlated color

temperature (CCT) uniformity compared to single self-adaptive phosphor coating. What`s more, after aging test, the CCT

uniformity of double conformal coating is still better than single self-adaptive phosphor coating.


2018 年 10 月 23-25 日中国·深圳


7

S201-201808122311

Fabrication and optical properties of white LED based on laminated remote phosphor film

Ning-ze ZHUO, Na ZHANG, Yong-hao CHEN, Peng JIANG, Shao-wen CHENG, Yue-hua ZHU, Hai-bo WANG

Institute of Optoelectronic Materials, Nanjing Tech University

Institute of Optoelectronic Materials of Industry

5 Jinchuanmenwai Road, Nanjing 210015, China

[email protected], +86-025-58592286

Abstract

Based on laminated and remote phosphor packaging technology, double layer phosphor film were prepared by hot pressing

method, the films then were packaged into white LED. Fluorescence spectrophotometer and the visible spectrum analysis

system were used to study the influence of the layer order of green and red phosphor films and emission wavelength on the

optical properties of white LED. Results show that the luminescent efficiency of radiation of blue-green-red type was improved

by 31.69% compared to the blue-red-green type, the color fidelity and color gamut index increased with the increasing of

wavelength of red phosphor film, the color fidelity and color gamut index reached the highest value 91 and104 at 660nm

respectively, in contrast, luminescent efficiency of radiation was inversely proportional to the wavelength; color fidelity

decreased with the increasing of wavelength of green phosphor film, and color gamut index raised first, then decreased, the

luminescent efficiency of radiation reach the highest value 300.7lm/W when emission wavelength of green phosphor film was

530nm.


2018 年 10 月 23-25 日中国·深圳


8

S201-201808131843

Thin Film Flip Chips and its Chip-Scale Packaging and Applications

Gang LI

ShenZhen Dadao Semiconductor Co., Ltd

Nanshan District, Shenzhen, Guangdong, China

[email protected]

Abstract

Thin Film Flip Chips (TFFC) are completely different from horizontal chips, flip chips and vertical chips in structure. It has

neither sapphire substrate as in horizontal or flip chips, nor metal leads necessary for horizontal and vertical chips. TFFC has the

features of small size, large working current and high reliability, making TFFC be ideal chips to emit lights in parallel for

central illumination and for mini LED and micro LED applications. This talk reports a series of key technologies for fabricating

TFFC, including multi-chip bonding and sapphire peeling based on high-precision, high-density and mass transfer mode, chip

bonding and sapphire substrate peeling based on single chip free-arrangement mode. The effects of different substrate structures,

chip design, bonding interface and conditions, as well as excimer laser parameters on opto-electronic properties of TFFC,

especially on the yield, are discussed. On the basis of optimizing process parameters and equipment conditions, the

industrialized batch production of TFFC has been realized firstly in China. When the geometric size of flip-chip is between tens

of microns and hundreds of microns, the effects of two patented technologies, i.e. electrode flattening and side wall protection,

on the leakage, yield and reliability of flip-chip and TFFC were studied. The ceramic substrate structure with good thermal

conductivity and independent control for a single flip chip lays a foundation for the application of flip chip in intelligent

automobile lighting systems, mini LED and micro LED. This talk also reports for the first time that two chip-level packaging

technologies (CSP) based on high-precision high-density mass transfer mode and single chip free arrangement mode have been

implemented on TFFC to fabricate various kinds of CSPLEDs with thickness less than 0.15mm (excluding substrate) in

commercial batches. At the end of the talk, the applications of various high-intensity illumination sources and their modules

fabricated by TFFC and chip-scale packaging technology in automotive lighting, stage and landscape projecting lights, portable

spot lighting, and projection lighting, as well as in the fields of mini-LED and micro-LED are discussed.


2018 年 10 月 23-25 日中国·深圳


9

S201-201808141514

Flip Chip LED for New LCD Display Backlight Technologies

YuHsuan Liu, Soonlee Tan

Elec-Tech Photoelectric Technology (Dalian) Co., Ltd

No.3 Xinxi Road, IT Industrial Park, Dalian Development Zone, Dalian, China

[email protected]

Abstract

Year 2018 is the 50th anniversary of the LCD Technology since the first twisted-nematic field effect LCD prototype was

developed in fall of 1970 by Wolfgang Helfrich. Its longevity exceeds that of CRT and Plasma displays and continues to

compete against OLED which was seen as its replacement technology a few years back. One key component for the continuous

improvement in the performance of LCD technology is the evolution of the backlighting unit. Replacement of Fluorescence

(CCFL) with LED light source enabled many backlight technologies such as WLED Edge Lit, WLED Direct Lit, Blue LED

with QD Enhancement Film, and Full Array Local Diming to cater to new LCD display technologies. Over the years, the LED

chip technology has also evolve from Lateral Chip to Flip Chip to meet the form, fit and function requirements associated with

each backlight technology. This report presents the use of innovative flip chip LED design and architecture to meet new LCD

display technologies for Smart Phone and TV.

In the first part, we present the use of a Flip Chip LED in a Chip Scale Package (CSP) to meet the bezel-less LCD display

requirements for high-end Smart Phone. The use of a highly efficient Flip Chip LED design with a unique form factor enable a

CSP package of 0.3T instead of a 0.4T Lead Frame Package.

In the second part, we present the use of a 18V High-Voltage (HV) Flip Chip LED architecture to meet the requirements of

local dimming for High Dynamic Range (HDR) TV. We discuss the electrical, optical and reliability characteristics of HV Flip

chip. Together with the used of SAC solder bumped Flip Chip structure, we enable a high yield and reliable Flip Chip in Lead

Frame Package.


2018 年 10 月 23-25 日中国·深圳


10

S201-201808150942

Design of High Condensing Searchlight based on Ultra High Bright LEDs

Zhiliang Jin, Peipei Wang, Weimin Li, Daxi Xiong

Research Center of Light for Health, Suzhou Institute of Biomedical Engineering and Technology

No.88, Keling Road, Suzhou New District, Jiangsu Province, 215163

Email: [email protected], [email protected]

Abstract

A novel searchlight based on Ultra High Bright LEDs will be proposed. Special packaging technology with excellent heat

dissipation technology makes the LED modules have highest power density and ultra-short focal length with large numerical

aperture optical system is presented to realize collimating illumination with low Fresnel loss. The distance between the light

source and the point where the illuminance is 1 lux has been calculated to be over 3km and the beam angle is 2.6°. It was

confirmed in a site experiment that the light ray from searchlight proceeds forward without any diffusion because of the narrow

beam angle.


2018 年 10 月 23-25 日中国·深圳


11

S201-201808151044

Phosphor-free monolithic white LED device with adjustable color-rendering index

Jie Zhao, Tongbo Wei, Junxi Wang, Jinmin Li

Semiconductor Lighting R&D center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China

E-mail: [email protected], Mobile：15007844826

Abstract

In recent years, GaN-based white LEDs are widely used in solid-state lighting applications[1,2]. Commercially, these LEDs

are generally manufactured by yellow phosphors on top of blue LED chips to enable white light emission[3]. However, using

this method these white LEDs have a low color rendering index owing to red emission deficiency in the visible spectrum. In

addition, other issues still require consideration such as the self-absorption of the phosphors, the low efficiency of the energy

transfer from the blue LED to the down-conversion phosphors，the degradation of phosphors and so on[4]. In order to overcome

the drawbacks, here, we report a phosphor-free monolithic white LED device with adjustable color-rendering index.

Firstly, on the plane of n-GaN, a hexagonal micro/nano-hole arrays are formed on SiO2 and as a subsequent selection mask

by photolithography and ICP pattern transfer and so on, as shown in Figure. 1. Then a three-dimensional structures (n-GaN) is

grown by MOVCD, which are trapezoidal hexagonal structures. Subsequently, InGaN/GaN multiple quantum well, AlGaN

electron blocking layer, and p-type doped GaN layer (p-GaN) are epitaxially grown on this basis. As shown in Fig. 2, is an SEM

image of trapezoidal hexagonal structures. Finally, a certain proportion of the mixed quantum dots which is filled between the

hexagonal structures and the quantum well form lighting source.

The device can avoid the drawbacks that using phosphors, such as the energy loss caused by the Stokes shift which would

bring a relatively short life-time for LEDs, the degradation of the phosphors, low-color rendering index and so on. The excitons

both in the quantum well (three-dimensional trapezoidal hexagonal structures) and in the quantum dots can perform

non-radiative energy transfer process and improve the luminous efficiency. In addition, adjusting the composition of In in the

quantum well makes the sidewall of the three-dimensional trapezoidal hexagonal structures emit blue light, and the upper

surface emit green light (or yellow-green light or yellow light) which wavelength longer than the blue light. Meanwhile, by

changing the ratio of the mixed quantum dots, the value and intensity of the wavelength can be adjusted and the high-color

rendering index can be achieved.

Reference [1]Shih-Chang SHEI, Jinn-Kong SHEU, et al. Emission Mechanism of Mixed-Color InGaN/GaN Multi-Quantum-Well

Light-Emitting Diodes[J]. Japanese Journal of Applied Physics, 2006. 45(4A): 2463-2466.

[2]Daehong Min, Donghwy Park, et al. Phosphor-free white-light emitters using in-situ GaN nanostructures grown by metal

organic chemical vapor deposition[J]. Scientific Reports. 2015.

[3]Kui Wu, Tongbo Wei, et al. Fabrication and optical characteristics of phosphor-free InGaN nanopyramid white light emitting

diodes by nanospherical-lens photolithography[J]. Applied Physics Letters. 2014. 115, 123101.

[4] Zhe Zhuang, Xu Guo, et al. High Color Rendering Index Hybrid Ⅲ-Nitride/Nanocrystals White Light-Emitting Diodes[J].

Advanced Functional Materials. 2016. 26(3): 36-43.

Fig. 1. the device of the full structure Fig. 2. an SEM image of a trapezoidal hexagonal structure


2018 年 10 月 23-25 日中国·深圳


12

S201-201808151641

Silicone Rubber for LED Encapsulant

Lingyu Wang, Pengli Liu, Laixing Li, Wang Chen, Shihai Yang, Haiting Zheng

Guangzhou Human Chemicals Co., Ltd.

No.62, Xinye Road, Huangpu, Guangzhou City, Guangdong Province, China

Abstract

Silicone rubber has attracted considerable attention from Light Emitting Diode (LED) manufacturers, because of its superior

insulation, excellent weather and UV resistance, outstanding thermal shock resistance. This article starts with the technical

principle used in silicone encapsulants synthesis, which shows how each raw material works. Then some product design

experiences are illustrated with an example of designing a silicone encapsulant with excellent sulfur corrosion resistance. The

future development trend of silicone encapsulants is also proposed, expecting that more researchers can draw their inspiration

from this article.


2018 年 10 月 23-25 日中国·深圳


13

S201-201808222057

Study on Phosphor Schemes in Full Spectrum WLED

Chao Liang, Junfeng Xu, Yibing Fu, Xiaoming Teng, Kai Liu, Bin Wu

Jiangsu Bree Optronics Co., LTD.

118#, Liquan Road Jiangning District, Nanjing, China

[email protected], 025-52706566,

Abstract

The white light full spectrum scheme of WLED can be defined as: Ra is higher than 95, R1~R15 is greater than 90, and close

to the solar spectrum in the emission spectrum. In this paper, the LED chip is used as the excitation source to excite the

phosphors to achieve the full spectrum WLED. Two kinds of phosphor converted full spectrum schemes are studied. Results

indicated that blue chip based full-spectrum WLED scheme present higher brightness than that of violet chip based

full-spectrum WLED. However, violet chip based full spectrum show much high advantage in spectrum structure and more

similar to sunlight.

Key Words: WLED, Full spectrum, violet chip, blue chip.


2018 年 10 月 23-25 日中国·深圳


14

S201-201808231543

Au/SiO2 core/shell nanoparticles enhancing photoluminescence of graphene quantum dots

Xiaojuan Song, Wen Ding, Feng Yun

Xi’an Jiaotong University

olid State Lighting Engineering Research Center, School of Electronics and Information Engineering, Xi’an Jiaotong

University, Xi’an 710049, China

[email protected]

Abstract

Graphene quantum dots (GQDs) have received much research attention, and its nanoscale structure exhibits the new phenomena

due to quantum confinement and edge effects that give its distinct physical, optical and chemical properties, commonly nonzero

bandgap and photoluminescence (PL). Up till now, tremendous efforts have been made to develop various synthetic methods for

GQDs. Here, The GQDs prepared by a facile microwave-assisted hydrothermal method show an excellent PL spectra possessing

the broadband emission ranging from deep ultraviolet to near-infrared in our lab. This method owns the advantages, such as low

cost, non-toxicity, simple operation, and the novel PL properties of GQDs shows the great application future in optoelectronic

devices. However, compared to other semiconductor quantum dots, GQDs show the lower photoluminescence quantum yields,

which will limit its commercial applications in optoelectronic devices.

With the local electric field enhancement resulting from the surface plasmon resonance (SPR) near metal nanoparticles

developing, we utilize the tailor-designed Au/SiO2 core/shell nanoparticles to enhance the luminescence of GQDs and the

gold-based plasmon field enhanced PL of GQDs can be observed. Futhermore, we obtain the maximum PL intensity after

controlling the distance between Au nanoparticles and GQDs by designing the thickness of SiO2 and the concentration of Au

nanoparticles, which make this attractive fluorescence material have great application potential in GQDs-based optoelectronic

device. It is significant to bio-monitoring based on liquid phase environment.


2018 年 10 月 23-25 日中国·深圳


15

S201-201808270755

Preparation of of carbon dots by microwave synthesis for white LED devices

Zhang Shengnan, Li Yufeng, Yun Feng


Solid State Lighting Engineering Research Center, School of Electronics and Information Engineering, Xi’an Jiaotong


[email protected]

Abstract

At present, the mainstream implementation of white LEDs is to apply YAG phosphor on the blue LED chip. The problem with

this method is that the lack of cyan and red emission results in a lower color rendering index(CRI) . To make full-spectrum

white LEDs with a high CRI,it is an effective way using a UV LED chip to excite multi-phosphors. The choice of phosphors

greatly affects the performance of white LEDs. Fluorescent carbon dots (CDs), as emerging quantum dots, are intriguingly

increasing attention for their outstanding properties, such as excitation-dependent luminescence, low cost, chemical inertness,

low cytotoxicity, high photostability, and excellent biocompatibility, which make them a promising color converter for

application in white LEDs.

However, applications of C-dots in solid-state illumination devices have been limited due to luminescence quenching induced

by aggregation of the particles after solidification. The fluorescence efficiency is significantly lower after solidification. In

addition, the fluorescence spectrum of CDs is mainly yellow-green light, which is relatively single. To achieve the full-spectrum

LEDs, it is necessary to further expand the spectrum range of CDs.

In our study, citric acid was selected as the carbon source, and CDs solution was prepared by microwave synthesis. By adjusting

the mass ratio of citric acid to urea, microwave power, microwave heating time, etc, the optimal process conditions were

obtained. Under this condition, the luminescence intensity of CDs solution was maximum. Then, to solve the strong

luminescence quenching, we disperse the CDs in the PVA matrix to prepare CDs/PVA film, which reduce the agglomeration

during the curing process, and makes the luminescence intensity in the solid state almost consistent with that of the solution

state. Finally, by choosing the ethanol as the dilution solvent, dimethylformamide and water as the reaction solvent respectively

in the preparation process, we obtain two kinds of CDs whose fluorescence ranges were blue light and green light respectively

under the excitation of near UV. We achieve a LED device composed of a new type of hybrid fluorescent material made by two

kinds of carbon nanodot. The color rendering index of the LED is 85. It makes up for the lack of the traditional LED device in

the blue light band, which is important for the development of the full-spectrum LED device.

mailto:[email protected]


2018 年 10 月 23-25 日中国·深圳


16

S201-201809092305

Matrix-Addressable Micro-Size Light-Emitting Diode Array using Two-Step Etching Method

Huamao Huang,1, 2, 3, * Haocheng Wu,2 Cheng Huang,1 Zhuobo Yang,2 Chao Wang,1 Hong Wang1, #

1Engineering Research Center for Optoelectronics of Guangdong Province, School of Physics and Optoelectronics, South

China University of Technology, Guangzhou 510640, China 2School of Electronics and Information Engineering, South China University of Technology, Guangzhou 510640, China

3Guangzhou Institute of Modern Industrial Technology, Guangzhou 511458, China

*[email protected], #[email protected]

Abstract

Micro-size light-emitting diode (LED) array is an important source for high-speed and large-capacity visible light

communication (VLC) system. In order to realize largescale integration of micro-size LED arrays, two-step etching method is

used to reduce the difficulty of etching technique for deep groove and improve the yield of electrode interconnection. The

electrical and optical properties of the matrix-addressable 8 × 8 array are reported, and the effects of the two-step etching

technique on the electrical and optical properties are explored.


2018 年 10 月 23-25 日中国·深圳


17

S202-201810131857

710 Mbps real-time communication system with phosphor-coated LED

Xiongbin Chen

(1)State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences,Beijing,

100083, China

(2) School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing,

101408, China

*[email protected]

Abstract

The bandwidth expanding technology of visible light communication system based on phosphor-based LED has been proposed.

The 710 Mbps real time visible light communication system has been demonstrated using a phosphor-based LED without blue

filter.


2018 年 10 月 23-25 日中国·深圳


18

S202-201807181650

LED tunnel lighting control based on ZigBee

Shujun Sun, Bo Li1, Nianyu Zou

School of Information Science and Engineering, Dalian Polytechnic University, Dalian, 116034, China No. 1st Qinggongyuan, Ganjingzi, Dalian, Liaoning, China

[email protected], 15309818790

Abstract

In order to solve the problem of tunnel lighting safety and energy waste, a tunnel lighting optimization system based on

wireless communication is established. According to different light intensity changes and traffic flow outside the tunnel, and the

related factors affecting the illumination in the tunnel, the system gives the dimming command through the algorithm to

optimize the illuminance of the lamps and lanterns. The simulation results show that the system can optimize the illumination of

lamps and lanterns, realize intelligent dimming controlled by single lamp in tunnels, and effectively save energy.

1 Bo Li ()

No. 1st Qinggongyuan,Ganjingzi, Dalian, Liaoning, China

e-mail: [email protected]


2018 年 10 月 23-25 日中国·深圳


19

S202-201808132346

Study on Matching Value of Illumination in Night Lighting Environments

CHEN Ailin1, LI Zaizhou1, HE Qipeng2, HE Xiaoyang1, WANG Zhisheng1, ZOU Nianyu1*

(1. Research Institute of Photonics, Dalian Polytechnic University, Dalian 116034, China;

2. Innovation and Service Center for Lighting Technology of Guizhou, Bijie 551700, China) * corresponding author: [email protected]

Abstract

Night lighting plays an important role in the field of crime prevention. The horizontal illumination and the vertical

illumination are important indicators to measure the proportion of crimes. In order to study the optimal match between the

illumination of the exit plane and the illumination of the vertical plane in anti-crime lighting, 12 sets of LED light environment

were set up in the residential area. Weber Fischer law is used to analyze the experiment, and the best matching relationship

between horizontal illumination and vertical illuminance in the field of crime prevention at 4m is concluded. The experiment

was analyzed with Weber-Faxler's law, and the best illumination matching relationship corresponding to the face clarity of 4m

distance was obtained. The results are referential for crime prevention by means of night lighting.


2018 年 10 月 23-25 日中国·深圳


20

S202-201808151715

Underwater Wireless Optical Communication and Underwater Solid-State Lighting based on RGB

Laser Diodes Mixed White-Light

Xiaoyan Liu1, Suyu Yi1, Yuxin Huang1, Honglan Chen1, Zeyuan Qian1, Runze Lin1, Xiaojie Zhou1, Gufan Zhou1, Xiaolin

Zhou1, Shuailong Zhang2, Xugao Cui1, Lirong Zheng1, Ran Liu1 and Pengfei Tian1* 1Institute for Electric Light Sources, School of Information Science and Technology, Engineering Research Center of

Advanced Lighting Technology, and Academy of Engineering and Technology, Fudan University, Shanghai, 200433, China 2Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada

*Email: [email protected]

Abstract

This study proposed and experimentally demonstrated white-light source by mixing red, green and blue laser diodes

(RGB-LDs) for wavelength-division multiplexing (WDM)-based high-speed underwater wireless optical communication

(UWOC) and large-area underwater solid-state lighting (SSL) simultaneously. The communication performance and underwater

white-light SSL quality were investigated experimentally at an underwater transmission distance of 2.3 m. For each LD, an

on-off keying (OOK) scheme was employed. To achieve both high-speed UWOC and large-area underwater SSL, optical filters

and optical diffuser were employed. Aggregate data rate of 6.6 Gbps and the Commission Internationale de L’Eclairage (CIE)

coordinates of (0.3298, 0.3390) were obtained. In addition, owning to the water attenuation, the underwater white-light SSL

characteristics under various distances were studied in theory.


2018 年 10 月 23-25 日中国·深圳


21

S202-201808152031

Visible Light Communication System with 815 MHz-Modulation Bandwidth Based on Micro-Size

Light-Emitting Diode and Post-Equalization Circuit

Huamao Huang,1, 2, 3, * Chao Wang,1 Cheng Huang,1 Haocheng Wu,2 Hong Wang1, #

1Engineering Research Center for Optoelectronics of Guangdong Province, School of Physics and Optoelectronics, South

China University of Technology, Guangzhou 510640, China 2School of Electronics and Information Engineering, South China University of Technology, Guangzhou 510640, China

3Guangzhou Institute of Modern Industrial Technology, Guangzhou 511458, China

*[email protected]; #[email protected]

Abstract

In order to get high modulation bandwidth in the visible light communication (VLC) system, the micro-size lightemitting diode

(LED) with the diameter of 60 μm and the equalization circuit (EQC) are used. The micro-size LED works under low current

density of 707.4 A/cm2 to extend its lift time. Four key parameters, including the resistance and the capacitance, in the EQC that

consists of a two-stage common-emitter transistor amplifier were modified to adjust the frequency response, and, thus, to tune

the 3-dB modulation bandwidth of the VLC system. The experimental results show that the 3-dB modulation bandwidth of the

VLC system can be expanded from 94.2 MHz to 815 MHz, if the EQC was applied and optimized


2018 年 10 月 23-25 日中国·深圳


22

S202-201808162021

Design of A Multi-wavelength LED Photo-rejuvenating System

Jing Chen1,2, Liquan Guo2*, Jiping Wang2, Yinhong Chen2, Qi Zheng2, Daxi Xiong2 1University of Science and Technology of China, Hefei, China

2Suzhou Institute of Biomedical Engineering, Chinese Academy of Sciences, New District, Suzhou, China *Corresponding author: [email protected]

Abstract

To realize cosmetic phototherapy, a multi-wavelength LED cold light source design method is proposed in this work, which

combines the 455nm, 595nm, 630nm, 661nm, and 828nm LED chips into a single light module. Compared with the

conventional phototherapies using laser or intense pulsed light, the proposed light source has the advantages of improved safety

and longer life time. The electrical design to drive the system is also proposed. The system can be used in different

photo-rejuvenating applications, e.g. whitening and tendering skin, treating acne, by choosing different wavelengths. Another

feature of this system is that the temperature of skin area exposed to the light can be monitored in real time. Experiments have

been implemented to test the radiant power density and uniformity. The results show that the maximally achievable power

density of the system is about 75mW/cm2; and the uniformity of spot is above 80%.


2018 年 10 月 23-25 日中国·深圳


23

S202-201808222149

Investigation of the quantum efficiency of GaN-based light-emitting diodes on PSS in high spatial

resolution

Chenyu Wang, Li Yufeng, Yun Feng




[email protected]

Abstract

Although high-power and high-brightness LEDs have begun commercial production, it is still difficult to prepare

high-efficiency LEDs under large currents, and the luminous efficiency of LEDs is significantly reduced with the increase of the

injection current, that is, the LED's efficiency droop problem. The etched pattern (PSS) on sapphire substrate, the technology of

regrowth LED is widely used, which is considered to effectively reduce the line dislocation density, improve the crystal quality,

increase the scattering, improve the light efficiency, and effectively improve the luminous efficiency. Recently, we successfully

fabricated a new micro-scale patterned sapphire substrate via laser drilling process, and we have found obvious enhancement on

the optical efficiency.

In this work, by employing scanning near-field optical microscopy (SNOM), we obtained near field micro-region PL and EL

images, which can compare the difference optical property of inside and outside of the hole on the patterned sapphire

substrates(PSS) in a more direct way. And, by the SNOM PL intensity mapping, we found that there maintains a relationship

between the PSS structure and spectrum intensity. The PL intensity is higher inside than outside the drilling holes, which is

represented more clearly in the 3D PL mapping. The FWHM outside holes is smaller than that outside hole, and the FWHM

outside holes broaden wider. As the laser power increases, the peak wavelength becomes blue-shifted. And when inside the

drilling holes, the droop efficiency can be reduced compared outside drilling holes.


2018 年 10 月 23-25 日中国·深圳


24

S202-201808280913

A Single-stage LED Driver Using Step-Down Cuk/LLC with APWM-PFM Hybird Control

ZENG Lu，LIN Wei-ming

College of Electrical Engineering and Automation of Fuzhou University

Fuzhou，China

[email protected],18779868749

Abstract

At present, the most of LED driver on the market is designed for worldwide line (90Vac ~ 265Vac) applications, and can not

meet the higher voltage input applications. Therefore, step-down Cuk PFC is proposed to be used in higher voltage input

applications (277-480Vrms) in the paper. A half-bridge LLC was used as a DC-DC isolation unit of the single-stage converter

and adopts an APWM-PFM hybrid control strategy to solve the problem that the conventional pulse frequency modulation

(PFM) control strategy leads to unsatisfactory input characteristics of the single-stage circuit and keep the LLC circuit's soft

switching characteristics. Therefore, the single-stage resonant converter proposed in this paper possess the advantages such as

low input and output current ripple, low stress of the power switch and high system efficiency etc. A 100W experimental

prototype was built in the laboratory, which verifies the feasibility of the proposed scheme. Within the entire input voltage

range, the zero-voltage switch-on of the switch and the zero-current switch-off of the secondary diode was obtained and the

system efficiency achieves up to 91.65% @ the 310Vrms input voltage and rated load.

Key words: higher voltage line; single-stage LED driver; APWM-PFM hybrid control; step-down Cuk/ LLC converter


2018 年 10 月 23-25 日中国·深圳


25

S202-201809061711

Visible Light Communication Audio Signal Transmission System Design

JIANG Xiao-tong; GAO Huan; LI Ping

Dalian Polytechnic University School of Information Science and Engineering

Address: No. 1 light industry garden, Ganjingzi district, Dalian City

Phone:13609868241 Email:[email protected]

Abstract

LEDs have excellent modulation characteristics and enable illumination and transmission of audio signals simultaneously. A

set of point-to-point visible light audio transmission system is constructed. The performance of the audio transmission system is

studied by using the oscilloscope waveform. The influence of different transmission distance and receiving half angle on the

amplitude value parameters are discussed. At the transmitting end, the audio signal transmitted by the MP3 player is amplified

and stabilized by the amplifying circuit, the LED is driven, the electro-optical conversion is completed, the receiving end uses

the photodetector for photoelectric conversion, and the signal is amplified and divided by the amplification filter and the

low-pass filter. Finally get a saturated distortion-free audio signal. The results show that the system's ultimate transmission

distance is 2m, and gradually decreases as the distance and the receiving half angle increase.


2018 年 10 月 23-25 日中国·深圳


26

S202-201809071408

Design of a low temperature drift undervoltage lockout circuit

-Used for GaN FET power driver IC

GUO Weiling*，DU Shuai，BAI Changqing，LEI Liang，ZHU Yanxu

( Key Laboratory of Opto-electronics Technology，Ministry of Education，Beijing University of Technology，Beijing 100124，China)

* Corresponding Author，E-mail: guoweiling@ bjut. edu.cn

Beijing University of Technology, No.100, Pingleyuan, Chaoyang District, Beijing, China

13439213815

Abstract

In order to improve the stability of the GaN FET power driven integrated circuit, the integrated circuits usually design

corresponding protective circuit modules, such as over-current, over temperature, under-voltage protection circuit, etc. In this

paper, combined with the characteristics of GaN FET, based on the 0.18 m BiCMOS technique, a novel UVLO circuit used in

GaN FET power driven integrated circuits is designed. The average temperature drift of turn on circuit voltage

threshold(VDDTH+) is 0.12V, the maximum temperature drift is 0.481V, the average temperature drift of turn off threshold

voltage(VDDTH-) is 0.03V, the maximum temperature drift is 0.142V; the VDDTH+ and VDDTH- are 4.241v and 3.885v; The

hysteresis voltage is 356mv between VDDTH+ and VDDTH-, improved the circuit anti interference ability. The simulation

results show that the circuit can output low voltage logic signals in under-voltage, and has low temperature drift and voltage

hysteresis function, which has important significance for improving the performance of GaN FET power drive integrated circuit.


2018 年 10 月 23-25 日中国·深圳


27

S208-201811071338

高效率、高可靠性多沟道 HB-LED 驱动电源关键技术

High Efficiency, High Reliability Driving Power Supply for Multi-Channel HB-LED Applications

马红波

西南交通大学

中国四川省成都市高新区西部园区西南交通大学

摘要：

随着全球范围内能源短缺和环境污染问题的日趋严重，节能减排任务刻不容缓，同开发可再生新能源同等重要。

据不完全统计，照明用电占据了全球总用电的20%以上。如果用HB-LED取代全部白炽灯和部分荧光灯，我国可节省1/3

的照明用电，相当于三峡工程全年的发电量。如何提高照明产品的能效、降低照明的能耗，对节约能源和减少环境污染

有着十分重要的意义。高亮度发光二极管 (High-Brightness Light Emitting Diodes, HB-LEDs)，因其高光效、环保、

长寿命、高显色性等优点，成为21世纪最有价值的“绿色”照明光源，已经成为继白炽灯、荧光灯和高强度气体放电

灯之后的第四代电光源[1-3]。世界各国政府已经开始大力推进HB-LED照明技术的发展，特别是欧美、日本等国已经制

定相应的时间表以淘汰低效的白炽灯。我国政府也制定了相关计划，如2003年就启动了国家半导体照明工程计划，将

研发高效节能的半导体照明产品列为《国家中长期科学和技术发展规划纲要(2006 - 2020年)》工业节能当中的重要内

容。

尽管 HB-LED 在照明领域节能效果明显，潜力巨大。但目前， HB-LED 要在用电量大的景观照明、通用照明和大

面积全色彩显示屏中真正发挥作用，还有很多难点和技术问题亟待研究和解决。典型的 HB-LED 照明系统主要由

HB-LED 芯片、灯具、驱动电源三部分构成[5]。目前，HB-LED 芯片设计生产和制造工艺已相当成熟，驱动电源却成为

HB-LED 照明发展的最大瓶颈。主要体现在：（1）短寿命的驱动电源与 HB-LED 寿命的不匹配；(2)驱动电源的低效率

与 HB-LED 产品高光效的不匹配，节能效果不佳。

本报告以报告人主持的国家自然科学基金《高能源效率、高可靠性 HB-LED 驱动电源关键技术》的科研成果为基

础，围绕如何设计高效率、高可靠性的 HB-LED 驱动电源，首先指出 HB-LED 驱动电源的主要要求：高效率、长寿命、

低成本、PWM 调光以及智能控制。以电力电子的视角，从驱动架构、电路拓扑、电解电容消去方法等角度进行讲述，

主要内容包括：(1)针对传统多级级联驱动架构，提出了高效率的 Twin-Bus 架构、将传统的三级驱动降为 2.2 级；(2) 提

出了适合于 Twin-Bus 架构的超低电压应力，效率大于 99%的 Twin-Bus 电流调节器；(3) 面向低功率应用，结合

Twin-Bus 架构，提出了无电解电容的的四种单级 AC-DC 电路拓扑；(4)面向高功率应用,提出了两种单级软开关电路拓

扑及相应的控制调制策略；(5) 基于纹对消思想和准谐振技术，开发了具有 PWM 调光功能的 HB-LED 驱动电源。

最后，报告指出，通过先进的电力电子技术，不但可以提高HB-LED照明驱动电源的效率和寿命，进而实现最大化的照

明节能。而且，将整个HB-LED照明系统的使用寿命提高到一个新的高度，降低HB-LED照明的使用成本


2018 年 10 月 23-25 日中国·深圳


28

S203-201810081030

Challenges for Plant Factory with LED Lighting

Toyoki Kozai

Japan Plant Factory Association

6-2-1 Kashiwa-no-ha, c/o Chiba University, Kashiwa, Chiba 277-0882, Japan

email: [email protected]

Abstract:

Fundamental concepts of photosynthesis of plants and LEDs for plant factory application are introduced for improving lighting

use efficiency. The complexity of light environment control to maximize the cost performance of plant factory is discussed for

getting an idea of smart LED lighting system related to phenotyping, information and communication technology, and artificial

intelligence. The smart LED lighting system for next generation plant factory is considered to be advantageous over the current

LED lighting system, because the environmental factors, resources (electricity, light energy, CO2, nutrient solution, and labor)

supply rates and their use efficiencies, and plant responses including rates of net photosynthesis, dark respiration, transpiration

and phenotype including 3-deminsional canopy structure can be measured continuously. Based on the concepts described above,

challenges for plant factory with LED lighting are presented for contributing to solving food-resource-environment trilemma.

Keywords: Artificial intelligence, Continuous measurement of photosynthesis, Environmental control, Phenotyping, Smart

LED lighting



2018 年 10 月 23-25 日中国·深圳


29

S203-201810081031

LED Lighting in Plant Factory for Lettuce Seedling Production

Dongxian He, Zhengnan Yan

Key Lab. of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs, China

Agricultural University

17 Qinghua East Rd., Haidian, Beijing 100083, China

email: [email protected]

Abstract

Effects of lighting environments including photosynthetic photon flux density (PPFD), photoperiod and light quality at seedling

stage on growth and quality of hydroponic lettuce (Lactuca sativa L. cv. Frill ice) at seedling stage and its subsequent cultivation

stage were conducted for high seedling quality. Hydroponic lettuce seedlings were grown under combinations of three levels of

PPFD (150, 200 and 250 μmol m-2 s-1) and three photoperiods (12, 14 and 16 h d-1) provided by three light quality: fluorescent

lamps (FL) with R:B ratio of 1.8, and LEDs with R:B ratio of 1.2 and 2.2, respectively. After the 20-day treatment during

seedling stage, lettuce seedlings were transplanted to same lighting environment as PPFD of 250 μmol m-2 s-1 with photoperiods

of 16 h d-1 for another 20 days before harvest. Results showed that leaf length and the ratio of leaf length to leaf width decreased

in a logarithmic way, while leaf and root dry weights of the seedlings increased linearly with increasing daily light integral. FL

led to larger seedlings with bigger leaves and higher leaf and root dry weights compared to LEDs. Leaf and root fresh weights of

harvested lettuces were higher in the seedlings grown under PPFD at 200 μmol m-2 s-1 with a 16 h d-1 photoperiod, regardless of

light quality at seedling stage. Generally, vitamin C and soluble protein contents of mature lettuce were higher when the

seedlings were grown under higher PPFD or longer photoperiod. These results indicated that PPFD of 200 μmol m-2 s-1 with

photoperiod of 16 h d-1 provided by LEDs with R:B ratio of 2.2 in plant factory was suitable for hydroponic lettuce (cv. Frill ice)

seedling production because of the good growth and energy saving.

Keywords: Daily light integral, hydroponic lettuce, ratio of leaf length to leaf width, R:B ratio, seedling quality, vitamin C

content


2018 年 10 月 23-25 日中国·深圳


30

S203-201810111050

Integrated LED lighting protocols for breeders, fertile eggs and broilers / layers

Jinming Pan,

Department of Biosystems Department, Zhejiang University

Hangzhou 310058, China

[email protected]

Abstract

Poultry is very sensitive to light environment. It's a new trend to design integrated LED lighting protocols carefully thinking

about different demands from breeders, fertile eggs and broilers / layers. We investigated the effect of LED spectra, lighting

duration and light intensities on the growth and behavior of breeders, fertile eggs and broilers / layers respectively. Optimal

lighting protocols were developed through a wide range of experimental tests in lab and demonstration systems. These suitable

lighting protocols significantly improved health and production performance of poultry. Products have been widely applied in

more than 600 famous enterprises in 27 provinces of China, such as Wens, CP, Yukou, Lihua, Huayu, Shengdile, Deqingyuan,

etc.


2018 年 10 月 23-25 日中国·深圳


31

S203-201810181645

Layer Pullet Preferences for Pight Colors of Light-emitting Diodes

China.

* Corresponding author: Shi Zhengxiang. E-mail:[email protected] G. Li123, W. Zheng124,B. Li124, Y. Zhao3, Z. Shi124*, Y.

Liu124

1. Department of Agricultural Structure and Bioenvironmental Engineering, College of Water Resources and Civil Engineering,

China Agricultural University, Beijing 100083, China;

2. Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, Beijing 100083, China;

3. Department of Agricultural and Biological Engineering, Mississippi State University, Mississippi, MS 39762, USA;

4. Beijing Engineering Research Center for Animal Health Environment, Beijing 100083,

Abstract

Light colors may affect poultry behaviors, well-being and performance. However, preferences of layer pullets for light colors are

not fully understood. This study was conducted to investigate the pullet preferences for four light-emitting diode colors,

including white, red, green and blue, in a lighting preference test system. The system contained four identical compartments

each provided with a respective light color. The pullets were able to move freely between the adjacent compartments. A total of

three groups of 20 Chinese domestic Jingfen layer pullets (54 to 82 days of age) were used for the test. Pullet behaviors were

continuously recorded and summarized for each light color/compartment into daily time spent (DTS), daily percentage of time

spent (DPTS), daily times of visit (DTV), duration per visit, daily feed intake (DFI), daily feeding time (DFT), feeding rate (FR),

distribution of pullet occupancy and hourly time spent. The results showed that the DTS (h/pullet·per day) were 3.9 ± 0.4 under

white, 1.4 ± 0.3 under red, 2.2 ± 0.3 under green and 4.5 ± 0.4 under blue light, respectively. The DTS corresponded to 11.7% to

37.6% DPTS in 12-h lighting periods. The DTV (times/pullet·per day) were 84 ± 5 under white, 48 ± 10 under red, 88 ± 10

under green and 94 ± 8 under blue light. Each visit lasted 1.5 to 3.2 min. The DFI (g/pullet·per day) were 27.6 ± 1.7 under white,

7.1 ± 1.6 under red, 15.1 ± 1.1 under green and 23.1 ± 2.0 under blue light. The DFT was 0.18 to 0.65 h/pullet·per day and the

FR was 0.57 to 0.75 g/min. For most of the time during the lighting periods, six to 10 birds stayed under white, and one to five

birds stayed under red, green and blue light. Pullets preferred to stay under blue light when the light was on and under white

light 4 h before the light off. Overall, pullets preferred blue light the most and red light the least. These findings substantiate the

preferences of layer pullets for light colors, providing insights for use in the management of light-emitting diode colors to meet

pullet needs.

Key words: poultry; light choices; monochromatic light; behaviors; test system


2018 年 10 月 23-25 日中国·深圳


32

S203-201808151555

Effects of Light Quality on Physiological Characteristics of Tomato Seedlings

Zhang Tong1, Chi Jianyi2,*,Zhang Yao2, Li Chengyu1,*, Zhang Hongjie1,Zhou Xiao2, Qin Xinmiao3,Wang Qiang2

(1Changchun Institute of Applied Chemistry Chinese Academy of Sciences, changchun, Jilin 13002, China; 2Baotou Rare

Earth Research and Development Center, Chinese Academy of Science, Baotou, Inner Mongolia 014030, China;3Baotou

Zhongke Ruifeng Technology Company Limited, Baotou, Inner Mongolia 014030, China)

Author for correspondence E-mail: [email protected]; [email protected]

Abstract

The effects of natural light and artificial light on chlorophyll and related enzyme activities in tomato seedling leaves were

studied by using LED lighting in a growth chamber. The results showed that： Under the condition of natural light source as

main light source, supplementation of ultraviolet (UV), violet (P), yellow (Y) could significantly increase the content of

chlorophyll a; supplementation of ultraviolet (UV), red (R), yellow (Y) can significantly increase the content of chlorophyll b;

supplementation of ultraviolet light (UV), red (R) can significantly increase the content of carotenoids. Ultraviolet (UV) and

violet (P) were beneficial to increase the activities of SOD, POD and CAT in tomato seedling leaves, while red (R) and yellow

(Y) light reduced the activities of SOD, POD and CAT.


2018 年 10 月 23-25 日中国·深圳


33

S203-201808171121

Effects of pre-harvest supplemental blue light treatment on post-harvest quality of Chinese kale

Xia Li, Jialin Tian, Houcheng Liu*

College of Horticulture, South China Agricultural University,

Guangzhou, 510642, China

[email protected]

Abstract

The influences of pre-harvest supplemental blue light on visual quality, nutritional quality as well as antioxidant activity of

Chinese kale during postharvest storage were investigated. Chinese kale were supplemented 50μmolm-2s-1 blue light for 10

days before harvest in greenhouse and the measure of flower stalk quality on 0, 2, 4 and 6 day after harvest (DAH) was carried

out. The results indicated that the higher contents of VC, total phenolics and flavonoids were maintained during whole

postharvest storage by supplemental blue light than the control. Meanwhile, supplemental blue light also significantly enhanced

the content of soluble protein and free amino acid and chlorophyll at 0 DAH. The leaf of Chinese kale treated with supplemental

blue light showed obviously more green than the control at 0 and 6 DAH. However, there was no significance in weight loss of

Chinese kale between supplemental blue light treatments and the control during whole postharvest storage. Thus, pre-harvest

supplemental blue light treatment might be a promising strategy to enhance the antioxidant activity and nutritional values and

allow a longer shelf-life of Chinese kale.

Keywords: Chinese kale; pre-harvest supplemental blue light; nutritional quality; visual quality; postharvest storage


2018 年 10 月 23-25 日中国·深圳


34

S203-201808171122

The Influence of Postharvest UV-A and Blue Light on Nutritional Quality Retention and

Antioxidant Elicitation of Cherry Tomatoes during Storage

Yamin Li, Jingjing Wei, Baoxing Xie, Houcheng Liu*

College of Horticulture, South China Agricultural University,

Guangzhou, 510642, China

[email protected]

Abstract

Postharvest UV and blue light exposure have been proven useful in delaying senescence and inducing the accumulation of

nutritional and health-promoting compounds in vegetables. However, few studies were conducted to determine the optimal light

wavelength and the most suitable storage time that maximized the quality of vegetables. In this study, nutritional and antioxidant

compounds of 4 cultivars of cherry tomatoes (green, yellow, red and purple) were investigated at 0, 6, 12 and 18 days after

harvest. There were 5 treatments (CK: no supplementary light; T1: 380 nm, T2:400 nm, T3: 430 nm, T4: 465 nm), 12 hours

(6:00-18:00) per day at PPFD of 50 μmol·m-2·s-1 and room temperature of 24℃. The results showed that the contents of

soluble sugar, soluble protein and free amino acids increased in yellow and purple cherry tomato fruits under UV-A (T2) and

blue light treatments (T3 and T4) compared to CK at 6 days or 18 days, while the content of soluble sugar in green (T1) and red

(T2 and T3) fruits decreased at 12 days. Compared with CK, the UV-A treatments (T1 or T2) had positive influence on the

DPPH scavenging activity and FRAP of red and purple cherry tomato fruits at 12 days, and blue light (T4) enhanced those

antioxidant abilities of green and yellow fruits at 18 days. UV-A treatments (T1) significantly improved the accumulation of

total phenolic compounds and total flavonoids in yellow and purple fruits at 12 days and blue light (T3 and T4) increased the

content of total anthocyanins in green and red fruits at 6 days or 18 days. Under UV-A treatments (T1 and T2), the lycopene

content increased in yellow, red and purple fruits at 6 days, but T1 had negative impact on the lycopene content in green fruits.

These results demonstrated that cherry tomatoes had specific responds to different wavelength of UV-A and blue light and it

need to take the different demand of cultivars in consideration when applying in production.


2018 年 10 月 23-25 日中国·深圳


35

S203-201809122013

Comparison of Two LED Spectrum Engineering Approaches for Horticulture Lighting

Yue Zhuo, Guoxi Sun, Youpu Ke, Chongyu Shen, Jay Guoxu Liu

ShineOn (Beijing) Technology Co., Ltd.

3/F, Building#3, Digital Planet, No.58, 5thJinghai Road, BDA, Beijing, China 100176

Abstract

With the improved efficiency of LED light sources and fast cost reduction in recent years, LED light sources have entered

into indoor urban agriculture and vertical farming. At present, LED light sources for horticulture lighting have two main

approaches to achieve required light spectra, one is monochromatic LED package and the other LED package with mixed

spectra of phosphor converted light. This paper analyzes and compares these two LED spectrum-engineering approaches. The

implementation methods and applicable scenarios of plant lighting will also be discussed.


2018 年 10 月 23-25 日中国·深圳


36

S203-201809141436

The effect of 580 nm-based-LED mixed light on growth, adipose skeletal development, and body

temperature of chickens

Jinming Pan, Yefeng Yang, Bo Yang, Yonghua Yu

Zhejiang University

College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China

[email protected]

Abstract

Though previous study indicated that the 580 nm-yellow-LED-light showed an stimulating effect on growth of chickens,

the low luminous efficiency of the yellow LED light cannot reflect the advantage of energy saving. In present study, the

cool white LED chips and yellow LED chips have been combined to fabricate the white×yellow mixed LED light, with an

enhanced luminous efficiency. A total 300 newly hatched chickens were reared under various mixed LED light. The

results indicated that the white×yellow mixed LED light had double-edged-sword effects on bird's body weight, bone

development, adipose deposition, and body temperature, depending on variations in ratios of yellow component. Low

yellow ratio of mixed LED light (Low group) inhibited body weight, whereas medium and high yellow ratio of mixed

LED light (Medium and High groups) promoted body weight, compared with white LED light (White group). A

progressive change in yellow component gave rise to consistent changes in body weight over the entire experiment.

Moreover, a positive relationship was observed between yellow component and feed conversion ratio. High group-treated

birds had greater relative abdominal adipose weight than Medium group-treated birds (P = 0.048), whereas Medium

group-treated birds had greater relative abdominal adipose weight than Low group-treated birds (P = 0.044). We found

that mixed light improved body weight by enhancing skeletal development (R2 = 0.5023, P = 0.0001) and adipose

deposition (R2 = 0.6012, P=0.0001). Birds in the Medium, High and Yellow groups attained significantly higher surface

temperatures compared with the White group (P = 0.010). The results suggest that the application of the mixed light with

high level of yellow component can be used successfully to improve growth and productive performance in broilers.


2018 年 10 月 23-25 日中国·深圳


37

S204-201810141949

New Developments in Lighting for Human Health

Robert Karlicek

Rensselaer Polytechnic Institute

110 8th St, Troy, NY, USA 12180

[email protected]

Abstract

The dynamic control of lighting spectral power distributions is well known to impact human circadian performance and, in turn,

human health. However, research is continuing to show that the relationship between lighting and circadian health and sleep

more complicated than simply reducing blue light at night. This work will discuss the use of programmed lighting for the

control of circadian phase response shifting, separation of physiological sleep processes from physiological circadian processes,

and emerging research on specialized spectral power distributions that may be effective for work lighting at night without

circadian disruption.


2018 年 10 月 23-25 日中国·深圳


38

S204-201807301645

Opportunities of Spectral Tuning in High Color Rendition

Shih Shun Chang, Ph.D., Global Applications Director

Lumileds, 370 W. Trimble Road, San Jose CA 95131, USA

Yanjun Zhang, Ph.D.,

Building No.19 & 20, Lane 299, Wen Shui Road, Shanghai, P.R.China, 200233

Abstract

When given a choice, consumers will typically choose light with higher color rendering. This is evidenced by the explosion

of CRI 90 and above products on the Energy Star Qualified Product List, where from March 2011 to 2017, CRI 90 and above

products increased from 41 to 850 different lamps. This is approximately an increase of a factor of 20! Besides assistance from

government programs, such as, the Voluntary California Quality Light-Emitting Diode (LED) Lamp Specification issued by the

California Energy Commission, advancements in both die and phosphor technology[1-2] also attributed to the increase in

adoption of CRI 90 products. In fact, the advancements are so great that 90 CRI lamps can meet and exceed the efficacy targets

as specified in the ENERGY STAR® Program Requirements Product Specification for Lamps Version 1.1. As customers ask

for higher color rendering capabilities, the debate of whether CRI is the correct metric for color rendering intensifies. This paper

will explore the possibilities of spectral engineering for color rendering optimization. In addition, we will review the metrics of

color rendering for both humans and machines.


2018 年 10 月 23-25 日中国·深圳


39

S204-201808072148

Circadian lighting: spectral optimization and lighting design innovation

Qi Dai1,2*, Wenjing Cai, and Yingying Huang1

College of Architecture and Urban Planning, Tongji University, 1239 Siping Road, Shanghai, China

Key Laboratory of Ecology and Energy-Saving Study of Dense Habitat (Tongji University), Ministry of Education, 1239

Siping Road, Shanghai, China


Abstract

With technology advancement in LED light sources and a growing understanding of the non-visual effect of light, applying

circadian lighting in indoor environment is becoming attractive. It is widely accepted that spectral power distribution (SPD),

corneal illuminance, timing, duration, and prior lighting exposure history are important factors that can affect the circadian

system. Among them, SPD and corneal illuminance are factors that can be designed and controlled by lighting experts, while the

rest are typically up to the end users to decide. In this presentation, we introduce our newly developed approaches for both

spectral optimization and lighting design innovation to achieve quality and efficient circadian lighting.

For the spectral aspect, we explore possible combinations of circadian effect and visual lit appearance (brightness or

dimness), under the constraints of general-lighting requirements such as white color coordinates, high color rendition, and a

reasonable range of correlated color temperatures. A color-mixing algorithm is developed to optimize lighting spectra for

desired circadian and visual effects. It could be a valuable tool for lighting designers to understand what combinations of

circadian and visual effects are achievable to suit the needs associated with different indoor environments;

For the lighting design aspect, (i) a rule-of-thumb equation is proposed to guide circadian lighting design with a focus on

indirect corneal illuminance: Ecor,avg(i) = (Φ/C1) ∙ ρ ρ'), where Ecor,avg(i) is the average indirect corneal illuminance at standing

or sitting positions, Φ is the initial flux from luminaires, C1 is a constant comparable to the total room surface area, ρ is the

reflectance of the surface where the first reflection occurs, and ρ' is the area-weighted average of surface reflectance. Through

numerical simulation with Radiance software and experimental validation, we demonstrate that our proposed simple equations

can provide accurate results for quick feedback at the field, therefore it can be very valuable in guiding practical circadian

lighting design; (ii) A big challenge of applying circadian light during the daytime is that it requires a level of “light dose” that

is much higher than what is pursued / achieved in current lighting design practices. Therefore, it is critical to find new ways of

lighting design that can effectively enhance indirect corneal illuminance. Our study compares the factors that contribute to

corneal illuminance and conclude that room surface reflectance can play a dominant role for this purpose. Therefore, improving

room surface reflectance and directing luminaire flux to the highest reflective surface are the recommended approaches to

achieve quality and efficient circadian lighting.


2018 年 10 月 23-25 日中国·深圳


40

S204-201808131100

Light distribution solids

— distinguish luminance distribution solids and illuminance distribution solids.

— Ling Xia1, *, Tingting Zhang1, Xiaofeng Liu1, Sylvia C. Pont2

1. College of IoT Engineering, Hohai University, Changzhou Key Laboratory of Robotics and Intelligent Technology,

Jiangsu Key laboratory of Special Robot Technology, Changzhou, China, (*: [email protected],)

2. Department of Industrial Design, Perceptual Intelligence lab, Delft University of Technology, Delft, The Netherlands

Abstract

The interaction between light and its surroundings (i.e. the geometry and materials) shapes the lighting distribution and

determines the appearance of scenes and its visual experiences. In this study, we introduced the concept of light distribution

solids by distinguishing luminance distribution solids and illuminance distribution solids. It is helpful to understand the spatial

and form-giving lighting effects on objects’ appearance and the relationship between two kinds of light diffuseness metrics

DCuttle and DXia (Xia, Pont et al. 2016, Xia, Pont et al. 2016). Furthermore, this study together with our previous study (Xia, Pont

et al. 2016, Xia, Pont et al. 2016) provide theoretical basis for the exploration of extracting photometry parameters out of HDR

panoramic photographs of scenes which are quite popular nowadays.


2018 年 10 月 23-25 日中国·深圳


41

S204-201808131505

Re-understanding the relationship between light and human beings based on the non-visual effects

of light

Wenqing Fang, Tuanqing Fang, Fan Yang, Chaopu Yang, Kaiqi Fang

Nanchang University

Nanchang, Jiangxi, P.R.China

[email protected], Mobil: 13807095537

Abstract

This paper try to reorganize the relationship between light and human beings, pointing out 6 common possible

misunderstandings in lighting and display: ①What's the best night light? Has human evolution adapted to modern lighting?②

Man always seeks bright at night, is it right? ③Can night lighting meet the physiological and psychological needs of human

beings at the same time?④Can people's physiological response to light be accurately measured within 2 hours before the

subjects were tired? Are our previous lighting products designed and evaluated correctly? ⑤ Should we abandon incandescent

lamps after their health effects of IR have been confirmed? ⑥What is the most important concern of lighting people at present?

Is there anything more important than affecting people’s vision? This paper suggests that human fertility may be more

important. A serious human reproductive crisis does exist in East Asia. Medically, there is a mechanism by which light could

affect human fertility. The similar mechanism has been verified by many animal experiments. But ethically, human fertility

could never be explored experimentally. Facing to the crisis or its signs, we had to use “regression to nature” as a last constraint

to conclude some “conjectures” roughly. In order to test these conjectures as much as possible, this paper reports a novel sensor

and instrument for evaluating Non-Visual Effect of Light by first using candlelight as a reference standard. With these

instruments, the author is beginning with the monitoring of the light environment of precocious children, wishing statistically

studying on the reproductive effects of light on humans. The authors are also trying to prove that menstruation originates from

changes in the moon's light over a month, which may give a dose reference to how dim that light start to affect human. If the

moon's dim light has a huge impact on the reproductive system, what about the powerful modern lighting? It is suggested

audaciously that the incandescent lamps should not be abandoned simply and rudely at least in the rooms or classrooms of

children, and at least before that LED Lamp with IR mimicking incandescent lamps could be developed.


2018 年 10 月 23-25 日中国·深圳


42

S204-201808131522

Maintaining Color Preference under Different Light Levels

Wenyu Bao and Minchen Wei*

Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong

[email protected]

Abstract

Substantial efforts have been made to investigate how to improve color rendition of light sources. It has been widely agreed

that a light source with a high color fidelity score may not always be preferred while sources with a higher saturation are more

likely to be preferred. This article reports a psychophysical study that was designed to investigate the color preference of an

artwork under five illuminance levels (i.e., 20, 50, 100, 200, and 480 lx). Nine nearly metameric stimuli with a gamut area (i.e.,

IES Rg) between 100 and 124 were created to illuminate the artwork at each illuminance level. The observers were asked to

choose the one under which the artwork had the most preferred color appearance. The results clearly revealed that the

illuminance level significantly affected the color preference of the artwork, suggesting the necessity to consider illuminance

level when specifying light source color rendition.


2018 年 10 月 23-25 日中国·深圳


43

S204-201808141732

Evaluating Colour Quality of Lighting: Why Meta-analysis Is Needed?

Q Liu1, 2*, Z Huang1, B Wu3, Y Liu1, H Lin1, W Wang1

School of Printing and Packaging, Wuhan University, Wuhan, 430079, China

Shen Zhen Research Institute, Wuhan University, Shenzhen, 518000, China

Guangdong JG Lighting Technology Co., Ltd, Dongguan, 523808, China

*Corresponding author: [email protected]

Abstract

The colour quality of lighting is usually assessed by psychophysical studies and the conclusions of those works are always

dependent on the corresponding experimental settings. In this contribution, the meta-analysis approach for this topic is

highlighted, which could derive a robust estimate closest to the truth and thus draw a more plausible conclusion. By revisiting

the past work, the limitation of single-case studies and the advantage of meta-analysis methods are comprehensively

demonstrated. In addition, a suggestion for sharing psychophysical data in further work is proposed.


2018 年 10 月 23-25 日中国·深圳


44

S204-201808141958

The Influence of Indoor LED Lighting on Depth Perception in Real World

Tingting Zhang*, Hexiang Cheng, Ling Xia, Xiaofeng Liu

Changzhou Key Laboratory of Robotics and Intelligent Technology, Jiangsu Key laboratory of Special Robot Technology,

Changzhou, China (*: [email protected])

Abstract

Lighting can influence people’s performance of eyes and their perception of depth cues. Both two factors are very important

for depth perception. Hence, lighting is expected to have effects on depth perception. The current study conducted a

within-subjects experiment to investigate the influence of three different indoor LED lighting environments on depth perception

in the real world. 23 participants were involved, and they were required to play a shooting computer game under the designed

lighting environment. Depth perception data were collected with a Depth Perception Tester both before and after the

experiment. The experiment showed that depth perception of the operators was always influenced by their physical and mental

state in the beginning, which was not changed by lighting environment. It was also found that the three lighting environments

used in the current experiment did not change depth perception. Hence, we could conclude that luminance between 350Lux and

750Lux is a safe range that does not influence depth perception.


2018 年 10 月 23-25 日中国·深圳


45

S204-201808142210

Lighting Quality Study of Shopping Malls in China Based on the Evaluation Experiment

Rui Dang1,*, Yanhui Bu1, Qingchen Wang1, Gang Liu1,*

School of Architecture Tianjin University, Tianjin Key Laboratory of Architectural Physics

and Environmental Technology

92 Weijin Road, Tianjin, China

*Corresponding email 1: [email protected]

*Corresponding email 2: [email protected]

Abstract

The lighting environment of the shopping malls will greatly influence the customer's visual comfort and product sales. This

experiment studied the lighting environment of jewelry stores with the highest lighting energy consumption in shopping malls.

The jewelry store scene which was built in the Key Laboratory of Building Environment Simulation had a total of 150 lighting

conditions. Then, we measured lighting parameters, and subjective evaluation of lighting quality (including lighting comfort and

commodities display effect) with 30 participants were carried out. We analyzed the experimental data to get the influence law of

lighting parameters on lighting quality. Finally, this paper introduces an emerging ensemble learning algorithm XGBoost

(extreme gradient boosting) to construct evaluation models of multiple lighting parameters for lighting quality in jewelry stores,

which were verified to have good accuracy. It is of great significance to save energy on the basis of ensuring the lighting quality

of the shopping malls.


2018 年 10 月 23-25 日中国·深圳


46

S204-201808150056

Using C-Support Vector Classification to Evaluate the Visual Comfort of University Classroom

Lighting

Rui Dang, Qingchen Wang, Gang Liu, Yanhui Bu

School of Architecture, Tianjin University

Room 601-4,School of Architecture, No.92 Weijin Road, Nankai District, Tianjin 300072, China

Corresponding email: [email protected]

Abstract

Considering the quality of the classroom light-environment will directly affect students' eye health and learning efficiency, it

is a problem to be solved that how to evaluate the visual comfort levels of the classroom light-environment and save lighting

energy on the premise of necessary visual comfort. Aiming at these problems, the study restored the classroom scene through

adjustable full-size light-environment simulation laboratory, in which 135 subjects participated in the visual comfort evaluation

experiment of the indoor light-environment. After features (illuminance and correlated color temperature) and labels (comfort

levels) preprocessed, the visual comfort classification models of desktop reading and blackboard reading were trained and

visualized using the algorithm of C-Support Vector Machine (C-SVM). The classification boundaries of different comfort levels

and the relationship between visual comfort and lighting parameters can be seen from the model visualization results, which has

guiding significance to classroom lighting design and evaluation.


2018 年 10 月 23-25 日中国·深圳


47

S204-201808151513

The impact of LED lighting on people’s work performance between different age groups

Ming Ronnier Luo, Meiling Wang, Yu Liu

State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou, CHINA

*[email protected]

Abstract

An experiment was carried out to study the work performance for the children, youth and aged groups including 12, 17 and

18 subjects respectively. Note that there have been very few studies to compare lighting impact on different age groups. For the

children group, 5 sources had 3 CCTs (3000, 4000, 5000K), each having Circadian Stimulus (CS) values of 0.22 and 0.42. For

the youth group, only 3 sources having the same 4000K as the young group were studied. Their CS values were 0.26, 0.41 and

0.44, respectively. For the aged group, there were 4 sources including 3000 K, 4000 K and 6500 K with CS about 0.4 and the

other 4000K with CS at 0.26. About 10 tests were employed including questionnaire (KSS, mood, PANAS, fatigue),

performance (d2, reading, Schulte grid) and eye fatigue (CFF and Landolt ring). It was found that the results from all three

groups showed a high CS source to have a higher work performance. For the youth group, 4000 K found to give a highest work

performance. For the aged group, a higher CCT showed a better performance. The results also showed a general trend, i.e. eye

fatigue and work performance have a negative correlation.


2018 年 10 月 23-25 日中国·深圳


48

S204-201808151713

Display white points under different ambient lighting conditions

1Rui Peng, 1Ming Ronnier Luo, 1Mingkai Cao, 2Jingyu Fang, 2Youn Jin Kim

1 State Key Laboratory of Modern Optical Instrumentation, Zhejiang University

Hangzhou, China 2 Huawei Technologies Co. Ltd. Shanghai, China

*[email protected]

Abstract

The purpose of this study is to investigate the image ‘white’ point on a display under dark environment and different ambient

illuminants. A single image composed of black text and white background was used. It was converted by means of the CAT02

chromatic adaptation transform from 6500K and Duv of zero, into 48 different white points varying at 6 CCTs and 8 Duv levels.

Through psychophysical experiments, observers’ subjective evaluations of neutral white and preferred white for 48 white

stimuli were obtained via a pair comparison method. The results showed that the most neutral and preferred image white points

were located at 7200K and 6000K respectively in the dark environment, and CCTs ranged from 6600 to 7300K and 5900K to

6300K respectively under different ambient illuminant conditions. It was also found that both the neutral white and preferred

white were below the Planckian locus. The chromaticities of the neutral white and preferred white shifted in the same direction

with the change of those of ambient lightings. The results can be proposed to achieve visual comfort on mobile devices under

various ambient lighting conditions.


2018 年 10 月 23-25 日中国·深圳


49

S204-201808151721

Design of LED Light for Stimulating Cells in the Study of Light Therapies

Jianfei Dong1,* and Zhuowei Zhang2,* 1Research Center of Light for Health, State Key Laboratory of Solid State Lighting, Suzhou Institute of Biomedical

Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China,*[email protected] 2No. 102 Hospital of PLA, Changzhou 213003, China, *[email protected]

Abstract

Among the wide and miscellaneous applications of light emitting diodes (LEDs), light therapies are probably one of the

most mysterious cases to the engineers of LED devices and systems, due to the profound biological principles involved therein.

Nevertheless, retrofitting the conventional light therapeutic devices with LEDs is also becoming a promising field to both

researchers and engineers. The long life time, high controllability, high bandwidth and the availability of diverse wavelengths

ranging from ultraviolet to infrared make LEDs excellent solutions for light therapies, and empower them with many more

freedoms in tuning irradiance, pulse durations and spectra than lasers, halogen lamps and other conventional light sources.

However, the existing literature still lacks sufficient criterion to design an LED light source so as to achieve optimal effects in

various light therapies. Besides, how human cells respond to the stimulation of LED light, especially in a quantitative sense, is

still far from being fully understood. Among the tremendous efforts along this research track, LED light design first needs to be

customized to biological experiments. This paper aims at investigating the specific requirements of light-cell interaction

experiments mainly in terms of the light spots and irradiance, based on which a method for designing a suitable LED light

source to stimulate cells will be proposed.


2018 年 10 月 23-25 日中国·深圳


50

S204-201808151910

Phototherapy blanket based on Blue GaN Mini-LED array

Yan Wang, Bo Lu, Feng Wei, Heshen Wang, Mengyuan Zhanghu, and Zhaojun Liu*

Department of Electrical and Electronic Engineering, Southern University of Science and Technology

Shenzhen, China

*Corresponding Author E-mail: [email protected]

Abstract

In this paper, a phototherapy blanket based on Blue GaN Mini-LED array is designed for the treatment of neonatal jaundice.

According to the height and three dimensions of the baby born for one month, the length of the flexible substrate of this

phototherapy blanket is 56 cm and the width is 50 cm. The GaN based blue LED chip with the smallest size of LED model of

the existing reverse structure of the market is GaN based blue LED chip with the size of 512 μm×157 μm, and the thickness is

140 μm, and the pixels are taken between pixels. The distance is 600 μm, and the size of the matrix is 500×660. The circuit of

this design is driven by direct drive. Because the open voltage of the LED chip of ETi-DB205A-BL is about 2.6 V, two number

5 dry batteries are selected as power supply, the positive pole of the dry cell is connected with the common anode, and the

negative electrode of the dry battery is connected with the common cathode. The ultimate strength of the model is measured at

453 nm, and the half height is 21 nm, which is the same as the maximum absorption peak of the absorption peak spectrum of

bilirubin, so the model is feasible.

Key words: Mini-LED array; Neonatal Jaundice; Phototherapy Blanket


2018 年 10 月 23-25 日中国·深圳


51

S204-201808152158

Lighting illuminance influence on blue light induced melatonin depression

Shanshan Tang1，Ya Guo2，Wentao Hao3，Shuai Huang2，Ke Wei4，Rongrong Wen3，Jianqi Cai2*，Aiqin Luo1*

1 Beijing Institute of Technology, Beijing, 100081, China

2 China National Institute of Standardization, 100191, Beijing, China

3 Kunshan Company of Human Factor Engineering Research and Development Center, Suzhou, 215333, China

4 Mianyang Institute of Product Quality supervision and Quality Inspection, Mianyang, 621000, China

*Corresponding Author: Jianqi Cai and Aiqin Luo

Abstract

Blue light in the range of 450~480nm has been proved to induce melatonin depression. However, the dose limit of blue light

has seldom been reported in previous study. In this study, human factor experiments have been performed to compare lighting

influence on melatonin emitting in lighting environments with correlated color temperature of 3000K and 5000K in ordinary

illuminance. It is indicated that blue light below 300lux has little influence on melatonin depression in the lighting environment

below 5000K. Consequently, illuminance is an important factor for trigger of non-visual photo-biology effect. In the lighting

environment with illuminance below 300lux, no distinctions can be found in the function of blue light induced melatonin

depression between non-visual effect luminaires and ordinary luminaires.


2018 年 10 月 23-25 日中国·深圳


52

S204-201808192209

Luminaire illuminance influence on imaging quality of human eye

Ya Guo1, Wentao Hao2, Shanshan Zeng1, Shuai Huang1, Shanshan Tang3, Ke Wei4, Rongrong Wen2, Jianqi Cai1,*

1China National Institute of Standardization, 100191, Beijing, China

2Kunshan Company of Human Factor Engineering Research and Development Center, Suzhou, 215333, China

3Beijing Institute of Technology, Beijing, 100081, China

4Mianyang Institute of Product Quality supervision and Quality Inspection, Mianyang, 621000, China

*Corresponding Author: JianqiCai (E-mail: caijq@ cnis.gov.cn).

Abstract

Aim: In lighting environment with the correlated color temperature of 5000K, visual function variations of subjects in three

illuminances during 45min visual task are compared to investigate the correlation between vision imaging quality and

illuminance.

Method: A total of 90 adults are divided into three groups: 350lux, 550lux and 750lux. Visual function parameters are collected

prior to and following visual task. Measured parameters are MTF and high order aberrations, which includesprimary

astigmatism, trefoil and sphere aberrations. One-way ANOVA analysis is performed on inter-group average values.

Result: MTF variation reaches the minimum value in 550lux illuminance. In 550lux and 750lux, MTF variations present similar

features. But in 350lux, the variation features are significantly different. For high order aberrations, significant differences exist

between 350lux and 550lux groups with p<0.05.The differences also exist between 350lux and 750lux groups with p<0.05.

Conclusion: Human eye is likely to obtain visual comfort to the full extent in 550lux. It is implied that parameters on wavefront

information, which includes MTF, primary astigmatism, trefoil and sphere aberrations, are effective to reflect visual fatigue

degree. These parameters are promising to be applied to diagnosis and assessment of visual fatigue.

Keywords: illuminance, wavefront aberration, visual fatigue


2018 年 10 月 23-25 日中国·深圳


53

S204-201808221809

The Effect of Office Lighting Strobe on Human Physiology

Xiaojie Zhao1,2, Dandan Hou1,2, Yandan Lin1,2, Wei Xu1,2*

1lnstitute for Electric Light Sources, Fudan University, Shanghai, China

2Engineering Research Center of Advanced Lighting Technology, Ministry of Education, Shanghai, China


Abstract

LED is generally used as office light sources, and the problem of stroboscopic effect becomes apparent with LED lighting in

working environments all over the world because of drivers and dimmers. So the physiological effect of working environments

with different lighting strobe on human is therefore proposed in this study. The experimental lighting conditions contained three

frequencies ( 100Hz/400Hz/ 1500Hz) and three modulation depths (10%/ 30%/70%). Ten healthy students were subjected to

each condition in a simulated office. Searching the Anfimov table task, transcribing task and filling in the scales were

executed in this experimental process, in which the participant’ s brainwave, pupil size, critical flicker fusion threshold (CFF)

were fully measured. The results showed that pupil size was found to have no significant effect in this experiment, but fatigue

scales, CFF before and after searing the Anfimov table task and brainwave of Occipital lobe all had significant results. Combing

the figure of Low-Risk Level and no observable effect level (NOEL) from IEEE Std 1789TM-2015 [1], the closer the condition

was to no-risk area, the greater power of the Alpha and Beta waves in the Occipital lobe, the clearer the consciousness. And

difference values of CFF before and after searching task showed that the fatigue significantly increased under 70%, the fatigue

scale was also in good agreement with this. And based on the results, guiding relationships were provided, which could be used

as proposal for the stroboscopic effect in office applications.


2018 年 10 月 23-25 日中国·深圳


54

S204-201808221810

Effects of CRI and GAI on Emotion and Fatigue in Office Lighting

Dandan Hou1,2 , Ye Ge1,2 , Yandan Lin1,2*




Abstract

This paper investigated the influence of Color Rendering Index on emotion and visual fatigue. By comparing the impact of

different CRI and GAI values on the color perception and emotions, getting the recommended values of CRI and GAI in the

office environment. In this experiment, GAI was used to assist Ra to evaluate the relationship of color rendering index with

emotion and visual fatigue. The test methods used in the experiment include color matching, critical flicker frequency test, and

emotion and fatigue scales, through which the experiment was conducted in different ways ranging from physiological

indicators, eye fatigue indicators, emotional and fatigue scales. The experimental results were analyzed by (ANOVA) variance

analysis, (PCA) principal component analysis, mean-value analysis, repeated measurement, and multivariate analysis. The

results showed that the participants are most likely to produce positive emotions in the condition of GAI = 120, Ra = 80, and

they are least likely to accumulate fatigue. Under GAI = 100, Ra = 100 cases, the mean value of the critical flicker frequency

(CFF) difference is the smallest, and participants are not prone to fatigue. GAI has a certain influence on emotions, while the

influence of Ra is smaller. Finally, GAI=100, Ra=100 and GAI=120, Ra=80 are easier to generate positive emotions.


2018 年 10 月 23-25 日中国·深圳


55

S204-201808221812

Study on Psychophysiological Effects of Window Glare on Human Body

Sijie He1,2, Yandan Lin1,2*




Abstract

Window glare is a common phenomenon in current office environment, which can easily affect office efficiency, causing

visual fatigue, eye discomfort and other issues. At present, there are two types of experiments in window glare study: real

window environment and artificial window simulation. In this paper, the effects of window glare on human were studied by

artificially simulated by LED light source, using the luminance and color temperature of window glare as variables, then use the

subjective and objective human data as standard to evaluate five kinds of glare metrics, DGP, DGI, UGR, VCP, and DGI. The

experiment found that the luminance of the window glare had a very significant influence on the subjective evaluation of the

subjects reflected in the De Bore scale (p=0.000<0.001). The color temperature of the window glare light source

(p=0.000<0.001) and the luminance of the window glare source (p=0.000<0.001) all have extremely significant influence on the

relative pupil size, which indicates that the relative pupil size reflects the body's obvious physiology of glare perception. When

the subjective evaluation De Bore score or relative pupil size was used as a benchmark, the evaluations of the five glare indexes

all had extremely significant correlations (p ≤0.05), and DGP shows the best performance.


2018 年 10 月 23-25 日中国·深圳


56

S204-201808291921

Quantitative Analysis of Full Spectrum LEDs for High Quality Lighting

Jay Guoxu Liu, Wei Tang, Yonghao Qin, Guoxi Sun, Chongyu Shen

Shineon (Beijing) Technology Co., Ltd.

3/F, Building#3, Digital Planet, No.58, 5thJinghai Road, BDA, Beijing, China 100176

Abstract

With the latest progress in new generation of phosphor and packaging design, higher quality, full spectrum, white LEDs

become possible. By engineering the spectrum power distribution (SPD), we have developed full spectrum light sources and

proposed methods for evaluating thelight sources’ color quality, spectral continuity, and eye-safety. The spectral continuity,

which is termed as Cs, quantifies the color quality of a light source in comparison to the reference illuminants. It can reflect the

difference of spectral power distribution between the measured source and the reference source. In order to provide a guidance

of minimizing harmful blue light of a spectral power distribution of a LED, we also defined the hazard blue light ratio which is

termed as Br and formulated by combining the methods used by IEC/EN 62471 standard and TÜV Rheinland. Several

approaches of creating full spectrum LEDs have been studied and evaluated from aspects including color rendering index (CRI),

IES TM-30-15, spectral continuity Cs, blue light hazard ratio Br. These assessments provide a helpful method to guide the

optimization of future light sources.

Keywords: White LEDs, High CRI, Spectral power distribution (SPD), Full spectrum, Spectral continuity, Blue light hazard

ratio, Fidelity index, Gamut index.


2018 年 10 月 23-25 日中国·深圳


57

S204-201809070854

Research on Healthy Light Environment Based on LED Large Space Industrial Lighting

Cheng Ruan 1，Yuan Tian1，Yaowei Huang1, Yang Wang 1,2 1Changchun Cedar Electronics Technology Co., Ltd. 2Changchun Institute of Optics, Fine Mechanics and Physics, Chinese

Academy of Sciences

No. 191 chaoqun street, high-tech industrial development zone, Changchun

[email protected] 0431-86155985

Abstract

Light plays a vital role in the human life. It causes not only visual effects, but also non-visual effects such as emotion and

circadian rhythms. Although the effort to fully understand the mechanism of light is still ongoing, how to design and develop a

perfect light source that is beneficial to human health is still an unsolved mystery. In this study, we committed to research on

human centric light quality and light health. Combined with the previous theoretical model, we propose the healthy light

environment design strategy in the field of LED large space industrial lighting. We take the example of FAW-Hongqi M

welding workshop and carry out systematic and comprehensive lighting renovation design to achieve green manufacturing and

human centric lighting (HCL). Finally, we expect to give some appropriate recommendations on the future healthy light

environment design in the field of LED large space industrial lighting.

Key words: light quality, light health, human centric lighting, LED, large space, industrial lighting


2018 年 10 月 23-25 日中国·深圳


58

S205-201810091105

Wide Bandgap Material Meatasurface：UV Optical Component and Device

Liancheng Wang

*

State key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering,

Central South University, Changsha Hunan, 410083, China

Corresponding author: Liancheng Wang: [email protected], [email protected].

Abstract

Ultraviolet (UV) photonics based device and equipment has various application in sterilization, military covert

communication, medical treatment, nanofabrication, Gem identification and so on. The traditional constituent UV

components are known to be inefficient due to high absorption loss of UV light, expensive, bulky and easily aging under

UV radiation. All-dielectric metasurface offers a promising way to control the amplitude, polarization, and phase of light

by engineering the size, shape and distribution of the its constituent elements. However, UV components based on

all-dielectric metasurfaces are difficult to be realized, due to significant absorption loss for most dielectric materials at the

UV region. Here we demonstrate the design of ultraviolet (UV) Optical Component and Device based on AlN with

ultrawide bandgap: UV metalens, UV routers and UV meta-reflectors.

The designed metalens is composed of high-aspect-ratio Aluminum nitride (AlN) nanorod array, with focusing

efficiency to be 40.1%, 41.9% and 29.1% at representative UVC (244nm), UVB (308nm) and UVC (375nm) a fixed

numerical aperture of 0.2. Focusing configurations including in-plane on-axis, off-axis, and out-of-plane have been

demonstrated.

UV routers for mono-wavelength and multiple wavelengths have been designed further, with the routing efficiency to

be 12.4% (244nm), 18.6% (first quadrant), 18.0% (third quadrant) and 7.17% (375nm) for the presented Bayer four

quadrant router. An improved design is necessary to reduce the crosstalk effect. Anti-counterfeiting based on Uv routers,

that is, barcode, QR is preliminarily presented.

We have designed UV reflector, which is composed of AlN nanodisks array metasurface on silica substrate. The UV

reflectance peak can be continuously tuned throughout the UV-A, UV-B and UV-C region by varying the structural

parameters, such as periodicity, height and diameter of the constitute AlN nanodisk. ED and MD resonances can be tuned

to be overlapped by adjusting the radius of the AlN nanodisk. Our designed AlN metasurface UV optical component

would promote the miniaturization and high-density integration of UV nanophotonics.


2018 年 10 月 23-25 日中国·深圳


59

S205-201809260959

Recent progress on the improvement of Deep Ultraviolet Light Emitting Diode Efficiencies

C. Q. Chen, J. Zhang, Y. Zhang, H. L. Long, Q. Chen, J. N. Dai, Y. Liu and S. D. Du

Huazhong university of Science and Technology

Luoyu Road 1037, Hongshan district, Wuhan, Hubei province, P.R. China

[email protected]

Abstract

AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) have attracted considerable attentions for their potential

applications in sterilization, water purification, dermatology, bio-agent detection and so on. Due to the large lattice constant and

thermal expansion mismatch between AlGaN epilayers and the widely used sapphire substrates, high threading dislocation

density (TDD) would occur in multi-quantum wells (MQWs) which will induce nonradiative carrier recombinations and low

internal quantum efficiency (IQE). As a consequence, the practical applications of AlGaN-based DUV LEDs are remarkably

limited owing to poor external quantum efficiency (EQE).

In this report, the growth of crack-free, thick AlN epilayer based on nano-patterned sapphire substrates (NPSS) was

demonstrated. The NPSS was processed by stepper lithography, ICP etching and wet etching. The NPSS patterns are well under

control and reproducible. AlN epilayers with thickness over 10 μm and atomically flat-surface were achieved on

pyramid-shaped NPSS. The full widths at half maximum (FWHMs) of X-ray rocking curves of (0002) and (10-12) planes were

165 and 185 arcsec, respectively. It shows excellent crystal quality of AlN epilayers which could improve IQE of DUV LEDs.

In addition, the total internal reflection (TIR) in DUV LEDs will severely restrict the light extraction efficiency (LEE) thus held

back EQE. Therefore, we employed moth-eye microstructures on the back of sapphire to reduce TIR of the interface at

sapphire/air and improve the LEE in the DUV LEDs. The experimental results show that moth-eye microstructures could greatly

improve the LEE and EQE of DUV LEDs.


2018 年 10 月 23-25 日中国·深圳


60

S205-201810150958

Effect of stress-relaxation layer in UVC-LEDs on sputter-deposited high-temperature annealed

AlN/sapphire

Kentaro Nagamatsu,* Kenjiro Uesugi, Kanako Shojiki, Liu Xiaotong, Shiyu Xiao, Yusuke Hayashi, Harumasa Yoshida, and

Hideto Miyake

Mie University, Tsu 514-8507, Japan

*E-mail: [email protected]

Abstract

White color Light-emitting-diodes (LEDs) has become essential to our life in the past ten years. A small flashlight can

brighten anytime, anywhere. It shows that LEDs are bright and long-life time with low cost. The lower cost, high

efficiency LED, and customized package are required for increasing an applying range to various types of applied

products. In recent years, UVC-LEDs that can be realized with the same Group-III nitride semiconductors are attracting

attention as the replacing mercury lamp as like white LEDs. These LED chips has a lot of issue such as the higher

produces heat, low light extraction efficiency, and high cost. There are a few groups reported improvement of external

quantum efficiency about the package of UVC-LEDs. However, these efficiency of LED at the wavelength of 255 nm is

less than 5%, the packaging technology will become the cutting edge of LED development soon. In this presentation, we

would like to share the present status of UVC-LED device, and we hope to lead to packaging development in UVC-LED.

One of our approaches is sputter-deposited high-temperature annealed (Sp-HTA) AlN/sapphire as the substrate of the

UVC-LEDs for reduction cost in large quantity. The AlN underline layer using Sp-HTA can be obtained high crystalline

quality and smooth surface. UVC-LEDs on the Sp-HTA AlN/sapphire using stress relaxation layer were fabricated

compared with conventional MOVPE-AlN template. As a result, the LED light output intensities were 1.5 times improved

than those of conventional MOVPE-AlN template. The detail characteristics of stress-relaxation layer on Sp-HTA

AlN/sapphire in UVC-LEDs will be discussed.


2018 年 10 月 23-25 日中国·深圳


61

S205-201807231951

Impact Ionization in Schottky-type Al0.4Ga0.6N Avalanche Photodiodes

Huan Yan, Wenle Zhang, Hao Jiang* State Key Laboratory of Optoelectronic Materials and Technologies, Sun

Yat-sen University Guangzhou 510275, China [email protected]

Abstract

Abstract Schottky-type Al0.4Ga0.6N solar-blind avalanche photo diodes under front and back illumination have been

characterized. Dark current was kept lower than 1 pA at the reverse bias below 100 V. The photodiodes achieved maximum gain

over 1000 under both front and back illumination conditions. The higher gain obtained by the back illumination is ascribed to

the avalanche process initiated by the holes with larger impact ionization coefficients. Impact ionization coefficients for holes

and electrons in Al0.4Ga0.6N have been extracted.


2018 年 10 月 23-25 日中国·深圳


62

S205-201808131551

Recessed-window 4H-SiC Avalanche Photodiode with Improved Single Photon Detection Efficiency

Linlin Su, Hai Lu*, Dong Zhou, Fangfang Ren, Dunjun Chen, Rong Zhang, Youdou Zheng

School of Electronic Science and Engineering, Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic

Materials, Nanjing University, Nanjing 210093, China ([email protected])

Abstract

4H-SiC avalanche photodiodes (APDs) are prior devices for weak ultraviolet light detection due to small size,

low dark current, high gain and quantum efficiency, which benefit from large bandgap energy, high carrier saturation

velocity and excellent physical stability of 4H-SiC material. Since the bandgap energy of 4H-SiC is 3.3 eV, at deep

UV region (<280nm) the light absorption coefficient of 4H-SiC is very high. As a result, for deep UV detection,

considerable photocarriers are generated in top contact layer due to the very short light penetration depth. These

photocarriers would recombine locally and contribute very little to photoresponse. A way to overcome the above

problem is to design a SiC APD with recessed-window, which can reduce light absorption and carrier recombination

in top contact layer while maintain high carrier collection efficiency.

In this work, SiC p-i-n APDs are fabricated with 150 μm diameter mesa (Fig. 1). To implement

recessed-window, a circular opening with 80 μm diameter is created in central mesa region by dry etching. The

recess depth are 205 nm and 330 nm of the top p contact layer, respectively. The device surface is then passivated by

thermal oxidation followed by 1 μm SiO2 layer deposited by plasma-enhanced chemical vapor deposition. All APDs

with no recessed-window (sample A) and with a recess window of 205 nm (sample B) or 330 nm (sample C) exhibit

very low dark current at pA level before avalanche breakdown (Fig. 2). The low bias quantum efficiency of the

recessed sample is increased by approximately 50% compared with the recess-free structure (Fig. 3). Moreover, with

a recessed-window, the single photon detection efficiency (@280nm) increases from 2% to 10% at a room

temperature dark count rate of 9 Hz/μm2 (Fig. 4). Therefore, a recessed-window 4H-SiC APD with low dark current

can be realized to improve single photon detection efficiency.

Fig. 1. The cross section schematic of the

recessed window 4H-SiC APD. Fig. 2. The current-voltage and gain-voltage characteristics of

the 4H-SiC APDs at room temperature.

Fig. 3. Responsivity curves of the 4H-SiC

APDs. Fig. 4. SPDE versus DCR curves of the 4H-SiC APDs.


2018 年 10 月 23-25 日中国·深圳


63

S205-201808131552

Spatial Non-uniform Avalanche Multiplication in 4H-SiC APDs

Linlin Su, Hai Lu*, Xiaolong Cai, Dong Zhou, Dunjun Chen, Fangfang Ren, Rong Zhang, Youdou Zheng

School of Electronic Science and Engineering, Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic

Materials, Nanjing University, Nanjing 210093, China

([email protected])

Abstract

4H-SiC avalanche photodiodes (APDs) working in Geiger mode are promising devices for weak ultraviolet light

detection. Recently, low dark current, high gain and high quantum efficiency SiC APDs have been successfully reported.

The best single-photon-detection-efficiency (SPDE) of SiC APDs is ~30%, which is a key parameter of Geiger mode

APDs for detecting ultra-weak light signal. However, the SPDE of SiC APDs should still have room for improvement

compared with the SPDE of the-state-of-art Si APDs, which could be higher than 50% in visible wavelength region. A key

factor to improve SPDE is to realize uniform avalanche. The gain uniformity of APDs has been traditionally studied by

using a focused-laser-beam based raster scan setup. Meanwhile, imaging hot carrier luminescence from APDs at

avalanche state is another method to characterize avalanche uniformity. In this work, the spatial uniformity of avalanche

multiplication is studied by imaging the APD’s luminescence pattern during avalanche.

The SiC p-i-n APD structure is grown and fabricated on 4o off-orientation n-type 4H-SiC substrate (Fig. 1). Due to

the relative low conductivity of the p contact layer, the luminescence from the APDs concentrates on the vicinity of the p

contact electrode due to current crowding effect (Fig. 2). Meanwhile, the luminescence region always starts from [1120]

side of top electrodes. As excess-voltage increases, the luminescence region gradually extends towards [1120] direction

(Fig. 2). A physical model is proposed to explain the non-uniform avalanche phenomenon (Fig. 3), in which multiplied

carriers could gain a lateral drift velocity due to the substrate’s 4o off-orientation towards [1120]. The asymmetric

accumulation of holes in the top p contact layer would lead to asymmetric screening of junction electrical field along

[1120] direction.

Fig. 1. The cross section schematic of 4H-SiC APDs.

Fig. 2. The top-view images and light emission

pattern of the SiC APDs at different avalanche current

levels.

Fig. 3. Model for the non-uniform luminescence

phenomenon from 4H-SiC APDs.


2018 年 10 月 23-25 日中国·深圳


64

S205-201808131701

High Performance (001) β-Ga2O3 Schottky Barrier Diode

Y. G. Wang, Y. J. Lv, X. Y. Zhou, H. Y. Guo, X. B. Song, X. Tan, S. X. Liang, Y. L. Fang, Z. H. Feng and S. J. Cai

National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute

Hezuo Road, Shijiazhuang, China


Abstract

A schottky barrier diode (SBD) without field plate was fabricated on a Si-doped N- Ga2O3 drift layer, which was grown by

halide vapor phase epitaxy (HVPE) on a heavily Sn-doped (001) β-Ga2O3 substrate. The thickness and concentration of N - drift

layer were 5 μm and 3.8×1016 cm-3, respectively. The reverse breakdown voltage (BV) and specific on-resistance (Ron) of the

fabricated Ga2O3 SBD were 825 V and 3.5 mΩ∙cm2, respectively, leading to a high Baliga figure-of-merit (BV2/Ron) of 194.5

MW·cm-2. Besides, a high current on/off ratio of 4.2×1010 was obtained.


2018 年 10 月 23-25 日中国·深圳


65

S205-201808160047

AlGaN Avalanche Photodiodes with bevel edge terminations

Haifan You, Zhijie Deng, Ruyue Yuan, Qianyu Hou

Nanjing University

No.163 Xianlin Avenue, Qixia District, Nanjing, Jiangsu Province, China, 210023

[email protected]

Abstract

Avalanche photodiodes (APDs) based on III-nitrides have attracted increasing attention due to their excellent potential in

offering high-sensitivity visible- or solar-blind detection. AlGaN APDs provide natural filters with tunable cutoff wavelengths,

making it possible to detect very weak ultraviolet (UV) signals under strong background radiation. However, AlGaN APDs are

suffering from difficulties such as high dislocation densities and low p-type doping efficiency. Another important challenge is

the edge premature breakdown resulted from the intense electric field at the junction bend. A proper edge termination to reduce

the edge electric field crowding effect is indispensable for AlGaN APDs.

Small angle bevel mesa is one of the few edge termination technologies to eliminate the edge electric field crowding effect. In

this letter, a high-temperature reflow process of photoresist for AlGaN materials was developed, and a very small bevel angle

was successfully realized. The edge electric field crowding effect is terminated and the peak of the surface electric field shifts

away from the junction, which is shown by the 2-D numerical simulations.

An 8° bevel mesa have been designed and fabricated for the first time on separate absorption and multiplication (SAM) AlGaN

APDs. APDs with vertical mesas are also fabricated on the same structure as reference. Compared with the conventional vertical

mesa APDs, the bevel mesa APDs show a significantly lower dark current, and realize an ideal bulk avalanche breakdown.


2018 年 10 月 23-25 日中国·深圳


66

S205-201808201042

Optimal Optical Design of UV-LED Curing System with High Illumination and Luminance

Uniformity

Peipei Wang, Zhiliang Jin, Daxi Xiong

Suzhou Institute of Biomedical Engineering and Technology，Chinese Academy of Sciences

No.88, Keling Road, Suzhou New District, Jiangsu Province, 215163

Email: [email protected], [email protected]

Abstract

In this paper, we propose a design of LED UV-curing system for automated industrial production lines. The main novelty of

this design is the application of compact packaged UV-LED module. The optical system uses conventional lenses rather than

specially designed lens or reflectors to collimate the rays, saving material costs and making for easier mounting. Through the

analysis and calculations, the optical design of the LED UV-curing system is optimized. The experimental results indicate that

our design in this paper have significant advantages in illumination intensity（>1.5W/cm2）and uniformity（>0.8）over traditional

UV-curing systems. The total power consumption is only 1.6KW


2018 年 10 月 23-25 日中国·深圳


67

S205-201808231543

Study of Laser Lift-off process with a strain-released bonding layers for Vertical UVC LED

fabrication

Maofeng Guo, Yufeng Li, Feng Yun, Ye Zhang, Xilin Su

Solid State Lighting Engineering Research Center, Xi’an Jiaotong University

School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China

[email protected]

Abstract

A study on film cracking in UVC-LED laser lift-off processed is presented. A strain-released bonding layer was newly

used during laser lift-off(LLO) process for fabrication of vertical UVC-LED to suppress cracking phenomenon. Since

GaN layers leading to film cracking caused by lattice mismatch, the epitaxial structures of UVC-LED with high Al

contents grown by MOCVD is often utilize an thick AlN buffer layer or AlN template. The 193nm ArF UV lasers used in

the LLO process are transparent to sapphire and strongly absorbed by AlN layer, thus making lift-off of the sapphire

substrate highly feasible. A sacrificed street area(SSA) is necessary for reducing the shock during LLO process and the SSA between each LED die is

etched to sapphire by ICP dry etch method. The Al-based reflector mirror was deposited on the top of epi-layer, then the

bonding layer were deposited on it and Copper tungsten substrate, this Ti/Au/AuSn strain-released bonding layer was employed

to alleviate the cracking after the LLO process, After bonding process, LLO was achieved by employing different laser fluence

from a 193nm excimer laser through the sapphire substrate. Successful LLO of a 1mmx1mm die size was attained without

cracking which was confirmed by optical microscopy and scanning electron microscopy analysis.


2018 年 10 月 23-25 日中国·深圳


68

S205-201809071951

Enhancement in the internal quantum efficiency and light extraction of deep ultraviolet AlGaN

multi-quantum well nanorod light emitting diodes

Shucheng Ge,1 Jiangping Dai,2 Na Gao,1 Shiqiang Lu,1 Penggang Li,1 Kai Huang,1,a) Bin Liu,2,b) Junyong Kang,1 Rong

Zhang,1,2 and Youdou Zheng2

1Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductors Materials and Applications, Xiamen

University, Xiamen 361005, China

2Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and

Engineering, Nanjing University, Nanjing 210093, China

Abstract

Highly-ordered AlGaN based deep ultraviolet nanorod light-emitting diode arrays were fabricated by nanoimprint

lithography and top-down dry etching techniques. Highly ordered periodic structural properties and morphology were obtained

by scanning electron microscopy and transmission electron microscopy. Compared with planar samples, cathodoluminescence

measurement revealed that nanorod samples showed 1.54-fold light extraction efficiency enhancement and a 15.6-fold internal

quantum efficiency enhancement for the emission from multiquantum wells at approximately 277 nm. The light extraction

efficiency enhancement can be attributed to the well fabricated nanostructured interface between the air and the epilayers.

Moreover, the reduced quantum confined stark effect accounted for the great enhancement in internal quantum efficiency.

FIG. 1. The top view (a), cross-sectional (b) SEM

images of the AlGaN NR LED arrays. (c) and (d)

represents the TEM images of single NR and AlGaN

MQWs respectively.

FIG. 2. (a) and (b) CL spectra of NR samples at 300

and 90 K respectively. (c) and (d) CL spectra of PLA

samples at 300 K and 90 K respectively.


2018 年 10 月 23-25 日中国·深圳


69

S205-201809072009

SiNW radial hybrid solar-blind photo-detector

Zhu Gao, Wen Ding, Xiaojuan Song，Zhenhuan Tian，Qiang LI，Ye Zhang，Maofeng Guo，Lei Zhao，Yufeng Li，Yun Feng

Solid State Lighting Engineering Research Center, Xi’an Jiaotong University

School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China

[email protected]

Abstract

The solar blind UV detector plays an important role in offshore oil monitoring, missile monitoring and other fields. At present,

the commercially solar-blind UV detectors are prepared on expensive III-V crystal substrates. If silicon can be used as the main

material, it is possible to produce a highly efficient silicon-based solar-blind detector which has a lower cost.

In this work, Quantum dots have been prepared and the PL test shows it has good down-conversion properties. Thus, quantum

dots may be used to directly convert ultraviolet light signal into optimized wavelength of a silicon detector.

A SiNW radial junction hybrid UV photo-detector was prepared. Firstly, vertical silicon nanowire arrays on an N-type single

crystal silicon wafer were prepared by metal-assisted chemical etching. Then a radial organic-inorganic heterojunction were

formed by spin-coating the PSDOT:PSS solution with different quantum dot (cesium-based perovskite quantum dot, graphene

quantum dot) onto the silicon nanowires.

The testing results showed that hybrid photo-detector with cesium-based perovskite quantum dot shows photoresponse of solar

blind signal and hybrid photo detector with graphene quantum dot shows photoresponse of UV light signal. Therefore the

Si-PEDOT:PSS radial junction hybrid detector is capable to be a UV detectors, and it is a new way of fabricating the high

performance UV detectors or solar-blind detectors in a low cost procedure.


2018 年 10 月 23-25 日中国·深圳


70

S205-201809072352

Orbital dependent quantum confinement at the valence band maximum in high-Al-content AlGaN

Li Chen, Wei Lin*, Jinchai Li, and Junyong Kang*

Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen

University, Xiamen, 361005, China

Abstract

AlxGa1-xN based quantum structures have attracted intensive attention in recent years due to their great potential

applications in ultraviolet (UV) and deep UV optoelectronic devices in spectral range down to 200 nm. [1, 2] It has been pointed

out recently that the high-Al-content AlGaN materials exhibit a very different valence band order. The valence band maximum

in high-Al-content AlGaN is occupied by the crystal field split-off hole (CH) band bringing in transverse magnetic

(TM)-polarized light emission. The TM-polarized emission referring to the light propagating perpendicular to the QW plane is

undesirable for light extraction from the c plane leading to low light extraction efficiency. Recent studies have shown that the

CH-band emission at the band edge exhibited abnormal behavior in contrast to the other emission, dependent on the external

electric fields due to the characteristics of constituent orbitals. [3] One arrives at the assumption that the quantum confinement is

dependent on the constituent orbital states at the top of the valence band. Knowledge of the quantum cofinement emerging from

underlying electronic and orbital states and their connections to the modified band structure at the interface is of interest for

efficienct optoelectronic device design in high-Al-content AlGaN. The first principle simulation provide qualitative insights into

the the interplay between the degree of freedom for charge confinement of the hole band and the orbital configuration

modulating by modify orbital configuration and symmetries. The orbital engineering is theoretically and experimently

demonstrated by varying the orbital configuration and evaluating the resulting transition rate. The Orbital dependent quantum

confinement at the valence band maximum presented in this work will spurred on the further improvement of optoelectronic

devices based on high-Al-content AlGaN.


2018 年 10 月 23-25 日中国·深圳


71

S205-201809111638

Study of epitaxial growth of high quality AlN and AlGaN - based deep ultraviolet light-emitting

diodes

Fujun Xu, Bo Shen

Peking University

School of physics, Peking University, Haidian District, Beijing, P. R. China

[email protected]

Abstract

AlGaN-based deep ultraviolet (DUV) light emitting diodes (LEDs) with the emission in the UVC wavelength region

(λ≤280nm) enable extensive applications in water/air purification, daily sterilization, surface disinfection, medical diagnostics

and biochemical agent detection. In this work, studies on high-quality AlN, AlGaN and subsequent high-efficiency AlGaN

multiply quantum wells as well as p-type AlGaN has been systematically studied.

First, high-quality AlN grown on nano-patterned sapphire or AlN templates has been investigated. The best X-ray

diffraction ω-scan full width at half maximum (FWHM) values for (0002) and (10-12) reflections of AlN reach 106 and 143

arcsec, respectively. The AFM image displays the steps are very straight and the value of root mean square (RMS) is 0.072nm.

Second, On the basis of the AlN with high crystalline quality, the AlGaN-based MQWs with target wavelength of 280 nm

was fabricated. Thanks to the low dislocations density of the 108 cm-2 order in the MQWs, a high IQE value above 80% for the

279-nm MQWs was obtained by the temperature-dependence PL spectrum measurement.

Third, realization of high hole concentration p-type AlGaN layer with a high Al mole fraction has been investigated. We have

developed a highly controllable metal atom desorption technique to realize the ultrathin AlGaN with higher Al mole fraction. By

Mg doping within this growth scheme, Mg atom concentration is great than 1019 cm-3. The hole concentration reaches a high

value of 6.7 × 1018 cm−3 with a mobility of 1.03 cm2/V.s at room temperature by Hall measurement.


2018 年 10 月 23-25 日中国·深圳


72

W201-201810160141

Impact of Basal Plane Dislocations and Ruggedness of 10 kV 4H-SiC Transistors

Victor Veliadis*, Ashish Kumar, Sanket Parashar, and Subhashish Bhattacharya *Deputy Director and Chief Technology Officer, PowerAmerica US Manufacturing Institute

Deptartment of Electrical and Computer Engineering, North Carolina State University

North Carolina State University, Raleigh, NC, USA

[email protected]

Abstract

Under bipolar current flow, electron–hole pair recombination at basal plane dislocations (BPDs) in the thick drift layers of

4H-SiC power diodes and transistors induces stacking fault (SF) formation and expansion, which causes forward-voltage

degradation. Although this phenomenon is primarily observed in bipolar devices, certain modes of unipolar device system

operation can use body diodes as freewheeling diodes, thereby generating bipolar current flow during parts of a power switching

cycle. BPD-induced SF-related degradation has slowed the wide adoption of high voltage SiC power devices including 10 kV

MOSFETs. In addition, the ruggedness of high voltage SiC devices needs to be proven out for volume market insertion. In this

paper, we investigate the effects of bipolar current stress on the electrical characteristics of high voltage SiC transistors by

subjecting ion-implanted gate vertical-channel JFETs with 100-μm drift epilayers (10 kV rating) to bipolar stress. Of the 17

JFETs tested, several exhibit severe forward gate-drain voltage degradation, while others show intermediate or no degradation.

The degradations are fully reversed by annealing, while non-degraded electrical characteristics remain unaffected by the

annealing. In the absence of BPDs, bipolar operation does not impact JFET electrical characteristics. Ruggedness of 10 kV 15 A

rated SiC MOSFETs is also investigated through their capability to withstand avalanche currents when subjected to unclamped

inductive switching. MOSFETs withstood single avalanche pulses with a maximum energy of 7.7 J at 34 A and a time duration

of 27 μs before the onset of catastrophic failure. At the MOSFET rated current of 15 A, the avalanche failure time is

extrapolated at greater than 40 µs, which is well above the typical fault clearance times of gate drivers and indicative of a rugged

device.


2018 年 10 月 23-25 日中国·深圳


73

W201-201810072032

Status and adoption prospects of WBG power devices -Swedish perspective

Mietek Bakowski*

Division of Optical Transmission & Power Electronics,

Research Institutes of Sweden (RISE) Acreo AB, Electrum 236, 164 25, Kista, Sweden


Abstract

SiC Power Center was founded in 2012 by RISE Acreo, Swerea KIMAB and the Royal Institute of Technology (KTH) with

financial support from Sweden s Innovation Agency (Vinnova) and Swedish Energy Agency. SiC Power Center is a platform for

cooperation between industry, research institutes and academia within the whole value chain from material to systems. Leading

industrial companies within automotive, energy systems and power electronics in Sweden and other research institutes have

been members of the Center: GE Power, Ascatron, Bombardier Transportation, EK Power Solutions, Eskilstuna

ElektronikPartner, Inmotion Technologies, Volvo Car, Volvo GTT, SEPS, SP and Swerea IVF.

The center has ambition; (a) to explore the potential of WBG electronics for future applications, increased competitiveness and

sustainable development by joining resources, competences and knowledge, (b) to promote the introduction of WBG power

electronics in products and applications where high energy efficiency, compactness and higher operation temperature provide

significant system advantages and (c) to inspire and involve others. The main objectives are increased adoption of WBG devices

in power electronic products and applications for energy savings and competitive advantages for Swedish industry.

Since last year the name of the center is WBG Power Center and it has at present 16 companies and research groups as members.

RISE Acreo is host of the center. RISE Acreo and WBG (SiC) Power Center organizes yearly conference (ISICPEAW,

IWBGPEAW) with focus on power electronic applications of WBG devices. The conference has been organized since 2007 and

starting this year the name of the conference is SCAPE.

Overview and highlights of the selected industrial and research projects financed by the Swedish Innovation Agency (Vinnova)

and Swedish Energy Authority programs and by SiC Power Center will be presented. The selected examples demonstrate

revolutionary gains in energy savings in WBG based power electronic energy conversion systems for a variety of applications. A

brief summary of related projects in the areas of material, technology and device R&D in Sweden, will be given.


2018 年 10 月 23-25 日中国·深圳


74

W201-201810091040

Recent progress in Silicon Carbide substrate technology

Dr.P.S.Raghavan

GT Advanced Technologies, 5 Wentworth Drive, Hudson, NH-03051

Abstract

High temperature, high power wideband gap semiconductors demand mastering the crystal growth process of materials like

Silicon Carbide (SiC). Today, SiC is grown from a gas or liquid phase process that involves the following: the generation of

reactants, the transport of reactants to the growth surface, adsorption at the growth surface, nucleation and finally crystal growth.

In this talk the different SiC crystal growth processes and recent advancements in SiC technology will be discussed.

In the case of Silicon Carbide, the solid phase coexists in equilibrium with its gaseous phase and hence it sublimes before it

melts. As a result, since there is no stoichiometric SiC liquid phase, it is impossible to employ congruent melt growth and

therefore it is not possible to grow SiC single crystals from melt, and instead crystal growth from the vapor phase is the

preferable technique for growing SiC crystals at a commercial scale.

The Lely method was the first to grow SiC crystals of different polytypes of sufficient quality for electronic applications. The

modified Lely method or physical vapor transport method (PVT) opened the way to industrialization of SiC and today SiC

crystals of diameter up to 200 mm are grown using induction or resistance heated sublimation furnaces.

The need for further improvements of quality and control of growth led to additional advances of the PVT process as well as the

exploration of other viable options. The principle of gaseous cracking for the supply of Si and C was further developed in order

to achieve growth rates comparable to the PVT method for the production of high volume wafers. The technique developed is

called high temperature chemical vapor deposition (HT-CVD). Further concepts were presented such as the Halide CVD

(H-CVD), Modified PVT (M-PVT) and a combination of HT-CVD and PVT reactor called Continuous Feed PVT (CF-PVT).

However, the latter techniques are far from producing commercial scale SiC wafers and are currently used at an academic level.

Lastly, in recent years, the growth of SiC bulk material from solution has gained interest from many researchers, as a potential

method for producing large size, high quality SiC wafers, but is not a mature method capable of achieving commercialization

status.

GT Advanced Technologies is a diversified technology company with crystalline growth expertise in silicon, silicon carbide and

sapphire. The company’s advanced materials deliver sustained value to the world’s top manufacturers in the global PV, power

electronics and photonics markets.

Leveraging its deep expertise in crystal growth technologies, GT Advanced Technologies has been involved in the development

of commercial scale silicon carbide boule production to address the growing needs of the power electronics industry since the

early 2000’s. The company’s extensive thermal modeling experience combined with equipment design has enabled unique

production processes resulting in high quality boules with low crystalline defects and commercial run to run reproducibility.


2018 年 10 月 23-25 日中国·深圳


75

W201-201808241702

Next Generation SiC-based Matrix Converters

Yuan Shu

Power Devices Group, Electronics Components Technology Division, ASTRI

Abstract

The matrix converter is a revolutionary power electronics technology that converts an AC waveform to another AC waveform,

where the output voltage and frequency can be set arbitrarily. It does away the need for a middle DC part, and reduces the ripple

in the output current significantly and can send back any current generated by the load to power supply, such as when a train

slows down. The key components in the matrix converter are bi-directional switches, made of silicon devices, which generate

significant losses in operation. Recent advances in third-generation semiconductor SiC can eliminate this key problem, and thus

unleash the superior advantages of the matrix converter.


2018 年 10 月 23-25 日中国·深圳


76

W201-201808142245

Passivation of 4H-SiC/SiO2 Interface with Phosphorus and Silicon Nitride

LIU Jia-jia

The 13th Research Institute

113 Hezuo Road, Shijiazhuang, Hebei province

Email: [email protected] Mobile: 0311-87091551

Abstract

In this paper, we describe experimental studies to determine the effects of phosphorus passivation for the 4H-SiC/SiO2

interfaces. Current-voltage test is used to characterize the interface quality. To obtain the interface state density lying within

0.2eV-0.4eV of the conduction band edge (EC), the C-V data is analyzed by Terman method. It is apparent that annealing in a

phosphorus solid state diffusion source can reduce the 4H-SiC/SiO2 interface states observably. What’s more, gate breakdown

field strength measurements for 4H-SiC MOS capacitors are also discussed. The phosphorus passivation silicon oxide and

silicon nitride are combined to reach not only low interface states but excellent gate breakdown field strength.



2018 年 10 月 23-25 日中国·深圳


77

W201-201809061942

Simulation, Fabrication and Characterization of 3300V/10A 4H-SiC power DMOSFETs

Shiyan Lia, Yunfeng Chena, Hao Liua, Runhua Huanga, Qiang Liua, S. Baia a State Key Laboratory of Wide-Bandgap Semiconductor Power Electronic Devices,

Nanjing Electronic Devices Institute

Nanjing, China


Abstract

Power devices of the 3.3 kV class are of much interest to various industries, particularly rail transportation and industrial

medium voltage motor drives. In this paper, 4H-SiC power DMOSFETs with breakdown voltage higher than 3.6 kV has been

successfully fabricated by using an 30 μm-thick, 2.8×1015 cm-3 doped drift epilayer. The JFET regions were implanted with

nitrogen ions to minimize the current spreading resistance. A 4H-SiC DMOSFET with an active area of 0.08 cm2 showed a

specific on-resistance of 19.7 mΩ-cm2 at room temperature with a gate bias of 20 V. The device shows a leakage current of 23

μA, which corresponds to a leakage current density of 142μA/cm-2 at a drain bias of 3.3 kV. In this report, the influence of JFET

region width to the DMOSFETs on-state current density was studied by a test MOSFET with an active area of 8.0×10-4 cm2.

Keywords: Silicon Carbide, DMOSFET, Breakdown Voltage, Specific on-resistance


2018 年 10 月 23-25 日中国·深圳


78

W201-201809091418

Design and Fabrication of 1.2kV/40mΩ 4H-SiC MOSFET

Runhua Huang, Hao Liu,Tao Liu,Tongtong Yang,Song Bai,Ao Liu, Yun Li and Zhifei Zhao

State Key Laboratory of Wide-Bandgap Semiconductor Power Electronic Devices, Nanjing Electronic Devices Institute

No.524, Zhong Shan East Road,Nanjing,China

[email protected]

Abstract

A 4H-SiC MOSFET with breakdown voltage higher than 1200V has been successfully designed and fabricated. Numerical

simulations have been performed to optimize the parameters of DMOSFET. The n-type epilayer is 10 µm thick with a doping of

1×1016 cm-3. The devices were fabricated with a floating guard ring edge termination. The drain current Id = 20 A at Vg = 20 V,

corresponding to Vd ≤ 1.6 V.


2018 年 10 月 23-25 日中国·深圳


79

W201-201809091629

Development of 1.7 kV 40 mΩ 4H-SiC Power DMOSFETs

Hao Liuab, Runhua Huanga Tao Liua, Ao Liua , Shiyan Li a , Song Bai a , Lijie Yang a, Longxing Shib

a State Key Laboratory of Wide-Bandgap Semiconductor Power Electronic Devices, Nanjing Electronic Devices Institute

Nanjing, China b National ASIC System Engineering Research Center Southeast University Nanjing, China


Abstract

In this paper, a1.7 kV power DMOSFETs in 4H-SiC were reported. The device utilized 14 um thick n-type epilayers with a

doping concentration of 7×1015 cm-3 for drift layer. The active area size of 1.7kV DMOSFET device is 20.5 10-2cm2. The

device was able to support a blocking voltage of 2 kV with gate electrode shorted to the source electrode. The device shows a

leakage current density of 68uA/cm2. At room temperature, the 4H-SiC DMOSFET showed a specific on-resistance (Ron,sp) of

8.2 mΩ-cm2 and an ID of 50A at VDS of 2.0V。The paper shows the blocking and conduction characteristics of the device

from 25℃ to 150℃ and the device demonstrated extremely fast, low loss swithing characteristics.


2018 年 10 月 23-25 日中国·深圳


80

W201-201809102226

Development of 6.5kV 50A 4H-SiC JBS diodes

Yunfeng Chen, Ji Tan, Song Bai, Runhua Huang, Rui Li

State Key Laboratory of Wide-Bandgap Semiconductor Power Electronic Devices, Nanjing Electronic Devices Institute

Nanjing, China


Abstract

A study of 6.5kV 50A JBS diodes based on 4H-SiC were reported. These high voltage SiC JBS diodes utilized 65 um thick

n-type epi-layers with a doping concentration of 1×1015 cm-3. The active area and total chip area of the JBS diodes were

75mm2 and 110mm2. Meanwhile, the FGR structure of 700um was applied for controlling the edge termination electrical

fieldof the JBS diodes. The JBS diodes were able to support a blocking voltage of 6.5 kV with leakage current lower than

1.5uA. Under forward bias of 3.70V, the forward current of the JBS diodes could reach 50A at room temperature. Barrier

height and ideality factor of the JBS diodes were extracted to be 1.26eV and 1.03. High temperature (425K) characteristics of

the JBS diodes were also measured and analyzed.


2018 年 10 月 23-25 日中国·深圳


81

W201-201809132116

Threshold Voltage Instability of 1200V SiC MOSFET Devices

Ao Liu1 , Tongtong yang1, Song Bai1 , Runhua Huang 1, Hao Liu1

1.State Key Laboratory of Wide-Bandgap Semiconductor Power Electronic Devices, Nanjing Electronic Devices Institute

Nanjing, 210016, China

E-mail: [email protected]

Abstract

1200V 4H-SiC MOSFETs have been designed and fabricated sucessfully. The drain current Id = 20 A at Vg = 20 V,

corresponding to Vd = 2.0 V. The stability of threshold voltage was studied soon. It is believed that the instability in device

behavior during gate bias stress is due to capture of electrons by the SiC/gate dielectric interface traps and the gate dielectric

near interface traps. A constant gate voltage of +20V/-10V is applied to the gate at a temperature of 150℃. The threshold

voltage are monitored for device stability. Compare with three other commercial devices,the devices show little variation in the

Vth.

Keywords: SiC MOSFET;threshold voltage ; interface states



2018 年 10 月 23-25 日中国·深圳


82

W202-201809292008

Current status and issues of AlGaN-based lasers

Motoaki Iwaya1, Tetsuya Takeuchi1, Satoshi Kamiyama1, and Isamu Akasaki1,2 1Faculty of Science and Technology, Meijo University, 468-8502, Nagoya, Japan

2Akasaki Research Center, Nagoya University, 464-8603, Nagoya, Japan

*Corresponding author Email Address: [email protected]

Abstract

UV laser light is widely applied field such as bio-/chemical photonics, material processing, and realization by semiconductor

laser is expected. AlGaN material is one of the most suitable materials to realize those devices physically. These lasers have

excellent characteristics such as compactness and high efficiency compared with gas lasers such as existing excimer lasers and

solid state lasers such as YAG lasers. Furthermore, these devices have a high potential because they have features such as being

able to realize arbitrary wavelength in the UV-C region from UV-A from 200 nm to 360 nm. Therefore, it is important to realize

a device that surpasses the existing UV laser while taking advantage of these merits. In this presentation, we discuss about

current status and issues of both AlGaN based UV lasers injection by current injection and electron beam excitation. In laser

by current injection, the full potential of these devices has been limited by low efficiency current injection due to the difficulty

of producing low resistivity p-type AlGaN alloys with high AlN molar fraction. Various approaches are being studied to solve

this problem. In this presentation, we would like to discuss the current situation and potential. In contrast, an alternative

approach to address this problem is the use of the electron beam excitation, which makes the conductivity control of nitride

semiconductors unnecessary. We obtained the electron beam excited laser in the UV region, using a nitride semiconductor

device with an AlGaN/AlGaN multiquantum well (MQW) active layers. We would like to introduce the results as well.

[Acknowledgments] This study was partially supported by the MEXT Private University Research Branding Project

(2016-2020), JSPS KAKENHI for Innovative Areas (No. 16H06416), JSPS KAKENHI for Scientific Research A (No.

15H02019), JSPS KAKENHI for Scientific Research A (No. 17H01055), and JST CREST (JPMJCR16N2).


2018 年 10 月 23-25 日中国·深圳


83

W202-201809211657

A Smart Gate Driver IC for GaN Power Transistors

Wai Tung Ng, Jingshu Yu

University of Toronto

10 King’s College Road, Toronto ON Canada L3T 2Y6

[email protected]

Abstract

Comparing with MOSFETs, driving GaN power transistors has many difficulties including low threshold voltage, narrow

tolerance between maximum and rated gate voltage, dv/dt and di/dt issues due to high slew rates. Current commercial GaN

driver ICs require external resistors for setting the pull-up and pull-down speeds. This leads to an increase in PCB space and

extra parasitics. Other drawbacks such as fixed output voltage levels, no precise timing control capability also limit their

applications. In this paper, a smart gate driver IC for GaN power transistors with current sensing feature, tunable output

resistance, tunable current sensing ratio and smart on-chip digital control is presented. It is designed to drive a d-mode GaN

HEMT in cascode configuration with a built-in low voltage silicon sense-FET. Together with an on-chip stack-based CPU, this

fully integrated gate driver IC allows flexible internal control, current mode regulation, active ringing suppression, and

efficiency improvement. The embedded CPU can generate PWM signals from 100 kHz to 50 MHz with an internal 100 MHz

system clock. Together with a 4-bit DLL block, the hybrid DPWM can achieve a resolution of 625 ps. Using the proposed

technique, ringing at the gate node of the HEMT is reduced by 86%, and current spike is reduced by 83% without sacrificing the

switching speed.


2018 年 10 月 23-25 日中国·深圳


84

W202-201808140813

Effect of GaN barrier layer thickness on morphology and optical properties of multilayer

InGaN quantum dots

kai Qu,a Hailiang Dong,a,b Zhigang Jia,a Shufang Ma,c Wei Jia,b Guangmei zhai,a Xuguang Liub and Bingshe Xu,a,c

a Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry

of Education, Taiyuan, Shanxi 030024, P. R. China b College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, P. R. China

c Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021 P.R.

China

Abstract

Light-emitting diodes based on InGaN have a problem called a green gap. InGaN quantum dots have proven to be a

promising structure to solve this problem due to their strong carrier localization effects. In this study, we fabricated InGaN /

GaN quantum dots and conventional InGaN / GaN multiple quantum wells by adjusting the growth mode and compared their

quantum confinement Stark and internal quatum efficiency by meas of intensity-dependent as well as temperature-dependent

photoluminescence measurements. The stress modulation effect of GaN barrier layer on multilayer InGaN quantum dots is

studied. It is found that as the thickness of GaN barrier layer increases, the stress accumulation phenomenon and the polarization

effect caused by stress are weakened, and more importantly, the residual stress is reduced. The density of the non-radiative

recombination center in the epitaxial layer is reduced. On the other hand, the temperature-dependent photoluminescence

spectrum indicates that the local state in the quantum dot decreases slightly as the thickness of the GaN barrier layer increases,

but the carrier can not be trapped by the non-radiative recombination center even if the temperature rises to room temperature.

By analyzing the stress field and the local effect of the carrier, it can be concluded that as the thickness of the GaN barrier layer

increases, the main reason for the increase in quantum efficiency in the quantum dot is the decrease in the number of

non-radiative recombination centers.

Key words: InGaN Quantum Dot,thickness of GaN barrier layer,Formation Mechanism, Optical Property

Corresponding author. Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of

Education, Taiyuan 030024, China

E-mail address: [email protected] (B. Xu).


2018 年 10 月 23-25 日中国·深圳


85

W202-201808152226

Modeling the Dynamic Power loss of AlGaN/GaN HEMT Power Electronic Device Operating in DCM and CCM Mode

Jianming Lei, Rui Wang, Bilei Ren

Nanjing University

Xianlin Road No.163, Qixia District, Nanjing, Jiangsu Province, China

[email protected]

Abstract

The silicon and other traditional material based incumbent technologies have reached their high frequency operation limits, the

AlGaN/GaN HEMT power electronic device opens up a new chapter on it. AlGaN/GaN HEMT power electronic device is fast

increasing attraction and represent the most promising candidate for the next generation power electronic device which is

focused on the relatively high frequency and high power, high voltage for the optimized system efficiency, EMI solution, size

and cost, because it has plenty of merits on high output current, high breakdown voltage, high operation frequency, high

operation temperature, small size and low power loss, low leakage current, no doping which are benefit from its nature wide

bandgap energy, high electron mobility and capability and polarization effect. The design should be compromised with power

loss, temperature rise, system size, and cost. Thus power loss evaluation for a higher frequency switch becomes of great

importance before the prototype design and measurement. This paper firstly presents a general high frequency switching power

loss model for the AlGaN/GaN HEMT power electronic device. The impact of real channel current in discontinuous conduction

mode (DCM) and continuous conduction mode (CCM) is considered. The trapping effect caused dynamic on-resistant and gate

lag, and the impact of the drain current in the turn-off transition are also taken into account. Numerical mixed-mode TCAD

simulation is supported to explore the switching processes. Experiments are used to test data and verify the model in DCM and

CCM mode by employing a new dynamic on-resistance extraction circuit. Furthermore, the impact of common source parasitic

inductor related to the power loss is studied by the two-order Laplace analysis. Finally, the model in quasi-resonant mode (QRM)

or in boundary conduction mode (BCM) with related high peak current and big duty cycle we proposed is benefit to achieve

lossless switch and even to release the switching speed limitation.


2018 年 10 月 23-25 日中国·深圳


86

W202-201808222038

Fabrication and characterization of high Q-InGaN quantum-well based microdisk

Mengqi Du, Yufeng Li, Peng Hu, Ye Zhang, and Feng Yun*

Key Laboratory for Physical Electronics and Devices of the Ministry of Education and Shaanxi Provincial Key Laboratory of

Photonics & Information Technology, Xi’an Jiaotong University, Xi’an, 710049, China

Solid-State Lighting Engineering Research Center, Xi’an Jiaotong University, Xi’an, 710049, China

E-mail: [email protected]

Abstract

With a wide and direct energy band-gap, emissions from Ⅲ-nitride semiconductors can cover the wavelength from deep

ultraviolet to the near-infrared. The research of nitride-based micro-cavity has attracted much attention for both physical insight

of lasing mechanism and widespread applications. Compared to the conventional F-P cavity and photon crystal micro-cavity,

WGM micro-cavity has its own strengths such as lower losses, lower threshold and higher quality factor. Here we conducted

ICP dry-etching and electrochemical etching on GaN films to obtain GaN based micro-disk to realize WGM (whispering

gallery mode) lasing. We introduced the EC etch to achieve the post structure under the disk, the thickness of the disk is about

145nm, in which the Q factor could be around 2000. Except for the WGM semiconductor lasers, the micro-cavity also can be a

bio-detector. Owing to the WGM mode, it is sensitive to the bio-molecules attached to the surface, which may cause the

resonance peak position of the micro-cavity to drift. It is significant to bio-monitoring based on liquid phase environment.

Fig.1 (a) the SEM of the micro-disk; (b) PL spectrum at different energies.


2018 年 10 月 23-25 日中国·深圳


87

W202-201808231543

Bio-sensor using high Q-GaN quantum-well based microdisk for FK506

Peng Hu, Li Yufeng, Yun Feng




[email protected]

Abstract

The phenomenon of whispering gallery modes (WGMs) within microresonators as a sensing modality has emerged as a

powerful contender for biosensing and liquid sensing. The spectral positions of the WGMs are determined by both the properties

of the resonator (e.g. diameter, shape, refractive index) as well as the surrounding medium. The latter feature allows changes in

the environment to be monitored via shifts in the spectral positions of the resonances. Therefore, we can detect the change of the

refractive index around the microcavity according to the change of the peak position to realize the detection of the liquid. At

present, passive cavities are often used for detection. However, in passive cavity testing, it is often necessary to use optical

fibers or waveguide structures to achieve coupling. The coupling effect is directly related to the coupling spacing, so the

interference caused by external environment vibration or other factors will affect the spectral output results, which can seriously

interfere with the final detection. On the other hand, active resonators are particularly interesting in this context as they allow

remote excitation of the resonator, thereby alleviating some of the practical limitations of passive resonator configurations.

We used InGaN quantum-well based microdisk as an active resonators to achieve liquid sensing. Thanks to the

combination of SiO2microsphere lithography and electrochemical etching, we prepared high quality microdisk, which has a

high Q factor. Then we used microdisk to detect anhydrous alcohol and isopropanol and found that it has a detection sensitivity

of 26.6nm/RIU, and we also have found it has a detection sensitivity of 0.005mg/ml for FK506.


2018 年 10 月 23-25 日中国·深圳


88

W202-201809031608

Growth of thick, continuous GaN layer on Si substrate and the location of C in GaN

Xuelin Yang1,*, Jie Zhang1, Shan Wu1, Haishan Zhang2, Lin Shi2, Weikun Ge1, Xinqiang Wang1, Ke Xu2, and Bo Shen1,*

1School of Physics, Peking University, Beijing 100871, P. R. China

2Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123, P. R. China


Abstract

Recently, vertical GaN devices, especially on Si substrates, have attracted much attention for high power applications due to the

low cost substrate. However, the performance is still lower than that of the vertical GaN devices on GaN substrates. The key

issue is that it is challenging to achieve low dislocation density and continuous thick GaN layer on Si substrates. In our previous

studies, we have achieved 3.0 µm thick continuous GaN layer using a single AlGaN buffer with low Al content. In the first part

of this work, by further employing this technology and using a new GaN dislocation filtering technology, the thickness of the

continuous GaN layer can be increased to as high as 7.3 µm. The total thickness of the epilayers including AlN and AlGaN

buffers on the Si substrate is about 8.0 µm. The full width of half maximum (FWHM) of the X-ray diffraction (XRD) rocking

curve for (002) and (102) scan is 299 arcsec and 314 arcsec, respectively. The thick, continuous GaN layers with low dislocation

density demonstrate the potential of high performance vertical GaN-on-Si power devices.

Carbon (C) doping is essential for producing semi-insulting GaN for power electronics. However, to date the nature of C doped

GaN, especially the lattice site occupation, is not yet well understood. In the second part of this work, we demonstrate that the

observed two new lines in the FTIR and Raman spectra originate from the local vibrational modes of substitutional C on the N

sublattice, i.e. isolated CN with local C3v symmetry. They are assigned to the nondegenerate A1 mode and the doubly

degenerate E mode of the C3v point group, respectively. Experimental data and first-principle calculations are in outstanding

agreement. We thus, for the first time, provide an unambiguous evidence of the substitutional C atoms occupying the N site in C

doped semi-insulating GaN and therefore bring essential information to the long-standing controversy.

Acknowledgements

This work was supported by the National Key Research and Development Program of China (Nos. 2016YFB0400104,

2017YFB0402901, and 2016YFB0400201).

References

1. J. P. Cheng, X. L. Yang, B. Shen, et al., Appl. Phys. Lett. 106, 142106 (2015).

2. J. P. Cheng, X. L. Yang, B. Shen, et al., Sci. Rep.6, 23020 (2016).

3. Y. X. Feng, X. L. Yang, B. Shen, et al. Appl. Phys. Lett. 110,192104 (2017).

4. S. Wu, X. L. Yang, B. Shen, et al., PRL, in revision (2018).


2018 年 10 月 23-25 日中国·深圳


89

W202-201809111546

Accelerated adoption of wide bandgap devices in automotive applications

Michael Heuken

AIXTRON SE

Dornkaulstr. 2, 52134 Herzogenrath, Germany

[email protected]

SiC and GaN power switches are making in-roads into industrial and automotive applications since reliability concerns are

addressed and commercial viability of end-products is achieved. Efficiency, power density and system cost reduction drive

adoption.

Vapor phase epitaxy is the key enabling technology for volume manufacturing of the material stacks required in WBG power

devices. In this presentation we will discuss production solutions for SiC and GaN power devices on 150 and 200 mm substrates.

As established on the tool-of-record in the GaN industry, AIXTRON’s AIXG5+C, full wafer level automation is driving

production throughput on 150 mm SiC wafers as well. Shortest process time enabled by high growth rate processes are leading

to significant cost reduction which is a key requirement for the industry.

The quality of epilayers is an important factor for the yield of device production as well as for the performance and reliability of

SiC devices. Influences of substrate properties on the defectivity and minority carrier lifetime in 4H-SiC homoepitaxial layers

are discussed.

To support the SiC product cost down roadmaps and the demand for highly uniform and reproducible epitaxial layers, in-situ

metrology becomes more and more important. In situ metrology can not only help to understand the epitaxy process but also

give feedback for the process development. Furthermore new technologies allow to use data from the metrology set directly for

advanced process control.


2018 年 10 月 23-25 日中国·深圳


90

W202-201808151241

Oxygen-Rich Defect Graphene Promoting AlN Nucleation and High-Quality AlN Film Epitaxial

Xiang Zhang1,Tongbo Wei

1, Junxi Wang

1, Jinmin Li

1

1State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing

100083, China

Abstract We have demonstrated high quality AlN film directly grown on oxygen doped graphene-substrate by MOCVD without buffer

layer. High-brightness blue LEDs with improved performance have been established. This revolutionary epitaxial method

shows great potential in optoelectronic devices based on Ш-nitrides. Experimental observations show that AlN nucleation

preferentially formed on oxygen-rich graphene rather than sapphire substrate. First-principles calculations were used to

deeply study the mechanism that oxygen doped graphene promotes nucleation of AlN.

Graphene film was directly grown on c-plane (0001) sapphire via catalyst-free atmosphere chemical vapor deposition (CVD)

method. Firstly, photoresist was spun on graphene-sapphire substrate, followed by nanosphere-lens explosure and developing

process to form regular hole pattern. Then the sample was treated under O2 plasma to etch away the exposed graphene film in

the hole and expose sapphire substrate. After cleaned in acetone for 5 mins, the residual photoresist was removed and the

nano-patterned graphene-sapphire substrate was obtained. The Schematic illustrations was shown as figure 1. Figure 1 |Schematic illustrations of high quality AlN film on nano-patterned graphene forming by nanosphere-lens

lithography.

a) Directly growth of graphene layers on sapphire

b) nano-patterned graphene by nanophere-lens lithography

c) AlN epitaxial on nano-patterned graphene

After loaded into the MOCVD charmer, trimethylgallium (TMGa), trimethylaluminum (TMAl) and NH3 were used as Ga, Al

and N precursors for growing GaN and AlN films. Firstly, the HT-AlN was grown at a nominal temperature of 1200 °C for 30s

Then the sample was carried out to study the mechanism of AlN nucleation on nano-patterned graphene-sapphire substrate.

As shown in figure 2(a), it was clear that AlN preferentially nuclear along the remaining graphene boundary. XPS showed that

the nano-pattern graphene was oxygen doped. First-principles calculations also revealed that oxygen-doped graphene

promotes AlN nucleation effectively. After growth for 1h, high quality AlN film was formed as figure 2(b).Raman spectrum

and XRD also showed the AlN film with high quality and almost stress-free.

Then u-GaN layer was grown at 1045 °C for 55 min followed by a n-doped GaN layer .Later, eleven periods of

InxGa1−xN/GaN active layers were grown at 735 °C /834 °C with 3 nm InGaN well layers and 12 nm GaN barriers. Finally,

LED deviceswith 45 mil2 size were fabricated using a conventional mesa structure.The LOP curve showed 19.1 %

enhancement at an injection current of 350 mA compared with conventional LEDs epitaxial on sapphire substrate.


2018 年 10 月 23-25 日中国·深圳


91

a b

Figure 2|SEM of （a）AlN nucleation on nano-patterned graphene-sapphire substrate

(b) AlN film after epitaxial for 60mins


2018 年 10 月 23-25 日中国·深圳


92

W203-201808061802

100nm and 60 nm GaN on Si MMIC Processes and Products

Marc Christian Rocchi

OMMIC

Abstract

The advent of advanced mmW telecommunication applications including 5G 28GHz and 39GHz mobile systems, has required

the development of high performance wide band gap MMIC processes and Products. In this respect , we at Ommic have been

able to demonstrate astounding mmW MMIC results using 100nm and 60nm GaN on Si processes from 20 GHz to 90GHz for

transmitting and receiving functions. Using GaN on Si we have equalled the performance of GaN on SiC processes but at a

significant lower cost enabling to meet the economics and the performance constraints of the infrastructure network as well as

the handset.

In this presentation , we will first review the GaN on Si processes in terms of RF performance and reliability . We will then go

over the performance of various 10W power amplifiers at 30 and 39 GHz with PAE as high as 35 % and 23 dB gain. We will

describe wide band LNAs with 20dB gain and 1.5 dB NF from 20 to 34 GHz. We will finally illustrate the capabilities of these

processes with 30GHz 5W and 2.7dB NF T/R chips and 600mW 90GHz power amplifiers.


2018 年 10 月 23-25 日中国·深圳


93

W203-201809141945

Gallium Nitride RF Schottky Barrier Diodes for Microwave Wireless Power Transmission

Jin-Ping Ao, Xiaobo Li, Taofei Pu, Taiki Hoshi, Tian Xie, Liuan Li, Xianjie Li, Shigeki Joseph Luke Fujiwara, Hiroshi Kitahata

1Tokushima University & 2Xidian University

2-1 Minami-Josanjima, Tokushima 770-8506, Japan & No.2 South Taibai Road, Xi’an 710071, China

[email protected]

Abstract

Wireless power transmission technology is a prospective technology, which can be used in various wireless applications,

such as wireless power charging, energy harvesting, ubiquitous power source, and wireless power distribution within a

building. In a microwave type of wireless power transmission system, a rectenna circuit is adopted to complete the RF to

DC conversion, in which a Schottky barrier diode (SBD) is widely used. However, there are fewer devices in the market

to satisfy the demands on a rectenna circuit with high conversion efficiency, such as low on-resistance, low

off-capacitance, and low turn-on voltage. In this talk, the development of GaN RF SBDs for microwave wireless power

transmission will be introduced. GaN diodes with reactively-sputtered TiN electrodes have lower turn-on voltage

compared with the diodes with Ni electrode, while GaN diodes with reactively-sputtered NiN electrodes have lower

reverse leakage current. GaN RF SBDs are expected to improve the RF/DC conversion efficiency of a rectenna circuit for

wireless power transmission.


2018 年 10 月 23-25 日中国·深圳


94

W203-201810031525

6-inch and 8-inch GaN on Si RF HEMT Technology for 5G Communication Applications

Xinke Liu,1 Hsien-Chin Chiu,2,* Hsiang-Chun Wang,2 Cong Hu,1

1College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, People’s Republic of China

2Department of Electronics Engineering, Chang Gung University, Tao-Yuan, Taiwan, R.O.C.

*E-mail: [email protected]

Abstract

The prevalence of 4G is driving the launch of international standards for new 5G mobile telecommunications networks. China

had started planning fifth generation (5G) wireless communication bands and frequency will be focusing on sub-six GHz band

at the first stage of 5G communication. The technology involved in 5G will require micro cells that connect to billions of

embedded devices, and many companies attended the event looking to get a head start in development of 5G hardware and

software. However, 5G base station system development is in infant stage because we had few key solidstate technologies for

high power base station industry. In addition, 5G communication system still exists some serious demands on power amplifier

linearity, output power density, and power added efficiency. In this talk, we will provide the 6-inch and 8-inch GaN on Si RF

HEMT technology solution for sub-six and millimeter wave bands. In addition, the DC/DC converter in micro cell base station

can be realized with high efficiency by using high uniformity p-GaN gate HEMT technology.


2018 年 10 月 23-25 日中国·深圳


95

W203-201808141609

Normally-off fluoride-based plasma treatment AlGaN/GaN HEMTs with maximum fT and fmax of

61GHz/130GHz using TiN-based source ledge

Ling Yang, Bin Hou, Minhan Mi, Peng Zhang, Jiejie Zhu, Meng Zhang, Qing Zhu, Yanrong Cao, Ling Lv, Xiaowei Zhou,

Xiaohua Ma, and Yue Hao State Key Discipline Laboratory of Wide Band-gap Semiconductor Technology, School of advanced

materials and nanotechnology, Xidian University, Xi’an 710071, China [email protected]

Abstract

Abstract Normally-off thin barrier AlGaN/GaN high mobility electron transistors (HEMTs) with a gate length of 0.1μm have

been fabricated on a SiC substrate. The use of fluoride-based plasma treatment combined with TiN-based source ledge produced

the normally-off device exhibits a threshold voltage of 0.6V, a saturation drain current density of 845mA/mm at a gate bias of

3V, a peak trans-conductance of 412mS/mm, a current-gain cutoff frequency (fT) of 61GHz, and a maximum oscillation

frequency (fmax) of 130GHz. A high transconductance (gm) and frequency performance E-mode AlGaN/GaN HEMTs were

achieved by TiN-based source ledge


2018 年 10 月 23-25 日中国·深圳


96

W203-201810011714

III-Nitride based RF devices: HEMT, HBT and filters

Yun Zhang

Institute of Semiconductors, Chinese Academy of Sciences

No. 35, Tsinghua East Road, Haidian District, Beijing

[email protected]

Abstract

III-Nitride semiconductors are promising for RF devices including high electron mobility transistor (HEMT),

heterojunction bipolar transistor (HBT), and high frequency filter due to their wide band gap, high breakdown voltage, high

mobility of 2D electron gas, and high acoustic velocity.

In Gallium nitride THz HEMTs, short-channel effect have impact on frequency because of the limit on transconductance.

Though Increasing Al components and decreasing thickness of barrier layer in HEMTs can suppress short channel effect, the

proposals inhibit the formation of ohmic contact on HEMTs. A regrowth n+-GaN source and drain electrode is an expected

method to reduce parasitic resistance in GaN base high frequency HEMTs researches. Regrown n+-GaN ohmic electrodes with a

low interface resistance of 0.004Ω·mm are fabricated in AlGaN/GaN HEMTs by high-doping MOCVD regrowth. In additional,

the HEMTs with the regrown GaN electrodes achieve a maximum oscillation frequency of 154 GHz and current gain cut-off

frequency of 64 GHz.

We demonstrate N-p-n structure AlGaN/GaN HBTs with SAG n-type AlGaN emitters by MOCVD. Compared with other

reported HBTs with base-emitter mesa dry-etching process, the p-type base contact shows ohmic contact characteristics owing

to dry-etching-free. As a result, the fabricated HBTs exhibit high β of 100, high JC of 8 kA/cm2 and power density of 75 kW/cm2

with a lowest Voffset <1V and Vknee <6.5V. The open-base breakdown voltage is 97 V@1μA, as a consequence the breakdown

field is 1.9 MV/cm. Besides, the current gain is increased with the emitter area decreasing. It is favorable for RF HBT devices,

which are expected to be used in PA in next generation communication. The performance of RF HBTs will be reported in the

report.

The working frequency of commercial LiNbO3 based surface acoustic wave (SAW) filters is below 3 GHz due to the low

acoustic velocity of LiNbO3 (3400-4000 m/s). As a result, AlN based SAW filter have attracted much attention for high

frequency applications thanks to its high acoustic velocity (5600-6000 m/s). SAW filters with a width of interdigital electrodes

of 2 μm have been fabricated on both LiNbO3 and AlN/Sapphire substrates. The center frequency (fc) of LiNbO3 based SAW

filter is 426.7 MHz, while the fc of AlN based SAW filter is 703.3 MHz, exhibiting a 65% increment. The quality factor of AlN

based SAW resonators is 1347, and the insertion loss of AlN based SAW filters is 8.71dB. The results indicate that AlN are very

promising for applications of ultra-high frequency filters and sensors.

http://www.baidu.com/link?url=P49KtjaqQz725nB6taDa1MVW81srxb_njeKC57GrVpwbI0eE3Tei6jPdjih2DS7C2H3VGvcNrP0KQ7LC_q03_-Q-dn6yNKkmIwEDrVYGmmvj4oB0_drjOsfe1-mmVAY2


2018 年 10 月 23-25 日中国·深圳


97

W203-201808231543

The fabrication of ITO materials with different morphologies by RF magnetron sputtering

Yuantao Zhang, Qiang Li, Feng Yun




Abstract

Indium tin oxide (ITO) films are widely used as a transparent conducting oxide (TCO) layer for a variety of practical

applications such as contact layers for solar cells, flat panel displays, and light-emitting devices. Due to novel physical, chemical

and electrical properties, ITO materials have got more attention in the scientific community .Generally speaking, The lower

dimension materials often have higher quality, fewer defects and higher surface-to-volume ratios, which are necessary for

nano-electronics, nano-mechanics, and nano-photonics. Until now, the fabrication of ITO materials with different morphologies

have not been studied systematically.

ITO materials can be synthesized by various ways, including thermal evaporation, sputtering, electron beam evaporation, pulse

laser deposition, and carbothermal reduction reaction. The growth of lower-dimension ITO materials (nanorod or nanowires) are

usually achieved through the vapor-liquid-solid (VLS) mechanism, where reactant vapors are absorbed by a catalyst (e.g., Au

nanoclusters) until super-saturation within the liquid alloy leads to the growth of nanowires and nanorod.

In our study, ITO materials with different morphologies ( film, particle, nanorod, and nanowires) have been fabricated on the

Si(100) by RF sputtering without catalyst. At the temperature of 500℃, different surface morphologies can be achieved by

adjusting the sputtering power and Oxygen flow rate. As shown in the Figure1 and Table1 (see attachment), the materials

dimension can be adjusted by the sputtering processes parameters. In addition, a droplet on the tip of every nanowires can be

found in the Figure1(d), which illustrated the growth of ITO nanowires through the self-catalyzed mechanism. Properties of ITO

materials had been tested, surface morphology, sheet resistance, and transmittance were respectively obtained by SEM, Four

Point Probe, and UV-Visible Spectrophotometer. As is shown in the Figure2(a) and Table2, with the decreasing of materials

dimension, transmittance decreased, and sheet resistance increased. ITO nanowires had been annealed due to lower

transmittance, Figure2(b) and Table3 shows that transmittance of ITO nanowire can be improved apparently after annealing.


2018 年 10 月 23-25 日中国·深圳


98

W203-201808272109

Simulation technology of GaN internal matching package device

J. Q. Lee, Y. N. Liu, J. Cao, Z. F. Hu, Y. X. Cui, and S. J. Cai

Hebei Semiconductor Research Institute

Hezuo Road, Shijiazhuang, China

[email protected],13833192002

Abstract

This paper reported a design method for GaN internal matching packaged devices was shown. Through testing structure

designing, introduced a method of measure S-parameter of bonding wire group and extract inductance of bonding wire. By

matching circuit packaging design and S-parameter measurement, established 3D electromagnetics model and simulated the

design, then comparing simulation results with measured results, optimized simulation parameters and settings, which improved

the accuracy of EM simulation. Demonstrate an internal matching power device with 2.1GHz-2.2GHz operation frequency and

55dBm output power. The input and output impedances measured by load-pull is close to the design value, which achieved the

expected design performance.


2018 年 10 月 23-25 日中国·深圳


99

W203-201809071651

A Modified Method for Sensitive Parameters of GaN HEMTs Large Signal Model

Ziyue Zhao, Yang Lu, Hengshuang Zhang, Chupeng Yi, Meng Zhang, Xinchuang Zhang, Xiaohua Ma and Yue Hao

Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices,

Xidian University, Xi’an 710071, China


Abstract

The role of device modeling in RF circuit has received increased attention across a number of disciplines in recent years.

Consequently, there are higher requirements on the accuracy of the model. Therefore, this paper intends to discuss the way to

build the Angelov Model of the Gallium Nitride (GaN) based high electron mobility transistors (HEMTs). For the classic

Angelov Model, there are many parameters to describe the trace about Ids curves. With these parameters, the accuracy of the

model can be ensured. However, for the Ids curve, one of the main obstacles is that the classic Angelov Model can hardly

describe its accuracy, especially when the gate voltage is lower than the knee voltage because of some sensitive parameters is

regarded as constant. In order to solve the obstacle, a modified Angelov Model changes the value of two parameters which are

sensitive for the output Ids curve is proposed in this paper. Fitting the formula according to the value of the parameter, finally,

the accuracy of the curve fitting can be improved, and the error can be reduced to 1%.


2018 年 10 月 23-25 日中国·深圳


100

W204-201810181515

Packaging of 10 kV SiC MOSFETs: Trade-Off Between Electrical and Thermal Performances

Cyril Buttay, Hugo Reynes,

SuperGrid Institute

Villeurbanne, France

Abstract

SiC transistors can achieve blocking voltages of 10kV and more. This makes them especially attractive for energy transmission

and distribution. Although SiC devices can in theory operate at high temperature (more than 200°C), the on-state resistance of

SiC MOSFETs exhibits a strong dependency on the junction temperature. As a consequence, it is shown that these transistors

must actually operate at a relatively low junction temperature (less than 100°C) to increase conversion efficiency and prevent

thermal runaway.

This requirement for high-performance cooling systems has consequences on the packaging technology: the corresponding

power modules must both offer a high voltage insulation and a low thermal resistance. In particular, there is a trade-off in the

thickness of the ceramic substrate located between the SiC devices and the cooling system. We propose a new substrate structure,

with raised features, which improves the voltage strength of a substrate without increasing its thickness. This structure is

demonstrated experimentally.


2018 年 10 月 23-25 日中国·深圳


101

W204-201809131542

Packaging of a Planar, Double-side Cooled SiC Power Module for Electric Vehicles

Yunhui Mei1, Xin Li1, Puqi Ning2, Shanqi Zhao3, Zhiping Liu4, and G-Q. Lu1,5 1School of MSE, Tianjin University, China

2Institute of Electrical Engineering Chinese Academy of Science, Beijing, China 3Jiangsu MacMic Science & Technology Co., Ltd., Changzhou, China

4China Electronic Technology Group Corporation Thirteenth Research Institute, Shijiazhuang, China 5CPES, Dept. of MSE and ECE, Virginia Tech, Blacksburg, Virginia, USA

Abstract

Advances in SiC wide bandgap semiconductor material and power device technologies have made possible

cost-effective power switches that have far superior performance metrics, such as lower on-resistance, higher

blocking voltage, lower switching loss, and higher operating junction temperature than the conventional silicon

power switches. However, packaging of these wide bandgap devices is becoming the bottleneck for their wide

ranging applications. The conventional packaging of silicon power modules with wire-bonding and device-soldering

on insulated-metal-substrates limits the potential of the high-performance SiC devices due to high parasitic

inductances, low heat-extraction capability, low die-attach and substrate reliability, and low-temperature interconnect

and encapsulation materials. With funding from an “863” project, we developed a packaging solution for making

low-profile, double-side cooled SiC power modules to enable fabrication of significantly higher power-density

converters for electric vehicles. Our packaging solution has three key innovations: (1) wirebond-free, low

parasitic-inductance device interconnection with cooling capability from both sides of SiC device; (2) sintered silver

bonding for improved thermal and electrical performance and thermo-mechanical reliability; and (3) high thermal

conductivity, high reliability silicon-nitride direct-bond-copper substrate. Descriptions on the module design,

materials selection, module assembly processes will be presented along with testing results of the modules for a 60

kW inverter.


2018 年 10 月 23-25 日中国·深圳


102

W204-201810021314

Challenges and Opportunities in Package and Integration of Wide Bandgap Power Devices

Laili Wang

Xi'an Jiaotong University

Xi’an Jiaotong University, Xi’an, 710049, China

[email protected]

Abstract

Compared with Silicon power devices, Wide Bandgap Power Devices have many advantages, such as lower conduction loss,

higher operating speed and temperature. Benefiting from these advantages, power density and efficiency of converters could be

improved significantly. However, these advantages could not be fully explored because of the limitation of today’s package

technology. This speech firstly addresses the challenges we are facing in package and integration of Wide Bandgap Power

Devices. Then new technologies are presented to solve the key issues. Finally, the roadmap as well as demonstration of new

package and integration technologies is presented.


2018 年 10 月 23-25 日中国·深圳


103

W204-201809261040

纳米铜用于功率半导体封装的工艺研究

叶怀宇

重庆大学

重庆市沙坪坝区沙正街 174 号邮编 400044

[email protected]

摘要：

现如今，功率半导体芯片正在从硅基向宽禁带半导体材料发展，其工作温度预计将会超过 300 摄氏度。为了保证功率半

导体器件正常工作以及提高其可靠性和寿命，研究适应高温、高功率的封装是非常有必要的。于此，纳米银是完美的解

决方案，然而昂贵的价格限制其只能在军工或者高端产品上使用。纳米铜作为替代方案。烧结后其性能与纳米银相差不

大，且价格适中。适用于大规模的工业应用。因此，我们系统地研究了纳米铜烧结的条件，以期探究达到最佳性能的工

艺参数。芯片与铜之间的热膨胀系数（CTE）差异很大，高温下产生的应力会导致封装失效，我们通过磁控溅射的方式

在芯片表面镀金属（镍、钼、钛），研究了中间层对于纳米铜烧结层的影响。此外，在空气、氮气、氩气的环境中烧结，

研究了气氛对于纳米铜烧结过程中的影响。温度也是重要的参数，提高温度可以增大烧结驱动力，我们分别研究了

200--300℃下纳米铜烧结层的性能。此外，300℃时氮气环境中，研究了无压力、5Mpa、10MPa 下烧结层的性能。


2018 年 10 月 23-25 日中国·深圳


104

W205-201809251257

Growth Mechanisms of h-BN on Sapphire Substrate by Metal Organic Vapor Phase Epitaxy

Yuhuai Liu*1,2, Xu Yang2, Shugo Nitta3, Markus Pristovsek3, Kentaro Nagamatsu3, Maki Kushimoto2, Yoshio Honda2, and

Hiroshi Amano3,4,5

1School of Information Engineering, Zhengzhou University, Zhengzhou, 450001, China 2Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8603, Japan

3Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan 4Akasaki Research Center, Nagoya University, Nagoya 464-8603, Japan

5Venture Business Laboratory, Nagoya University, Nagoya 464-8603, Japan

*[email protected]

1. Introduction

Hexagonal boron nitride (h-BN) is a promising candidate for neutron detectors and deep UV devices [1,2]. There are many

reports on h-BN flakes growth on transition metals by chemical vapor deposition (CVD), but it is difficult for industrial

applications due to the quality issues. Metal organic vapor phase epitaxy (MOVPE) can provide wafer scale of h-BN with

optimized equipment and growth conditions. However, since the first report of h-BN by MOVPE [3], there are quite few reports

regarding the MOVPE growth mechanisms of h-BN on sapphire substrate.

2. Experimental Results and Discussion

The BN films were grown on c-plane sapphire substrate by pulsed mode MOVPE at

growth pressure of 3.85 kPa. The growth temperature varied from 1030ºC to 1330ºC.

Triethylboron (TEB) and ammonia (NH3) diluted in hydrogen (H2) gas were used as boron

and nitrogen precursors, respectively. Each growth cycle contains 1 s for NH3 and 2 s for

TEB [4,5].

A ~60 nm-thick BN film was grown on sapphire substrate at 1330°C.The cross-sectional

TEM image taken along zone axis [11-20] is exhibited in Fig. 1(a). Two distinct layers

with different structures are found in the epitaxial BN film. In the upper layer (Zone I), the

film shows a well-oriented layered lattice and highly ordered stacking sequence of basal

planes, suggesting h-BN is formed in this layer. In contrast, the interlayer (Zone II) between

the layered BN and sapphire substrate exhibits a remarkable difference from the layered BN

on the topside. There is no clearly ordered crystalline arrangement and visible layered

structure. As shown in the Figs. 1(b) and (c), electron diffraction patterns are employed to

further examine the interlayer and topside layered BN. The upper ordered layer shows

separated spots following the hexagonal lattice arrangement, indicating dominating

hexagonal phase BN in the layer rather than turbostratic or amorphous. On the contrary, a

ring-shaped diffraction pattern is visible for the interface interlayer, indicating amorphous phase dominates this interlayer. EELS

analysis proves that Al L2,3 and O K edges are found in the amorphous interlayer but not detected in topside h-BN film,

indicating that sapphire may play an important role in the interface amorphization by providing Al and O.

Acknowledgements

This work is partially supported by JSPS KAKENHI #17J05229, NIMS, JST-SICORP, JSPS and RFBR, MOST-NKRDP

(2016YFE0118400), and KPSTHP (172102410062).

References

[1] H. X. Jiang and J. Y. Lin, Semicond. Sci. Technol., 29 (2014) 084003 (14pp).

[2] H. X. Jiang and J. Y. Lin, ECS J. Solid State Sci., Technol. 6 (2017) Q3012-Q3021.

[3] Y.Kobayashi, T.Akasaka, J. Cryst. Growth, 310 (2008) 5044–5047.

[4] X. Yang, S. Nitta, K. Nagamatsu, S.-Y. Bae, H.-J. Lee, Y. Liu, M. Pristovsek, Y. Honda, and H. Amano, J. Cryst. Growth,

482 (2018) 1-8.

[5] X. Yang, S. Nitta, K. Nagamatsu, S.-Y. Bae, H.-J. Lee, Y. Liu, M. Pristovsek, Y. Honda, and H. Amano, Appl. Phys.

Express, 11(2018) 051002 (5pp).

Fig.1 Cross-sectional

TEM image taken along

zone axis [11-20] (a)

(left), electron diffraction

patterns for zone I (b) and

zone II (c) (right).


2018 年 10 月 23-25 日中国·深圳


105

W205-201809071651

Realization of fast growth of n-type doping single crystal diamond through MPCVD method

Hong-Xing Wang*, Zhangcheng Liu, Fang Lin and Dan Zhao

Institute of Wide Bandgap Semiconductors, Xi’an Jiaotong University, Xi’an, 710049, China

*[email protected] Abstract

With the development of semiconductor technology, high-power-high-frequency electronic devices have begun to spread

rapidly. Compared with typical semiconductor materials, such as SiC and GaN, diamond has attracted much more attention for

high potential usage in power devices like Schottky barrier diode, metal oxide semiconductor field effect transistors and p-n

junction diode due to its favorable properties such as high breakdown field, high thermal conductivity, high mobility, and low

dielectric constants. However, there exists two main barriers to use diamond. One is the crystal size and quality, another one is

the n-type doping technology. Nitrogen, a common group-V impurity, creates a deep impurity level at 1.7 eV below the bottom

of the conduction band. Another group V element P has been successfully doped in diamond for both (111) and (001) surface

and shows a relatively shallower doping level. Since then, much progress has been achieved. All these works applied a relatively

low methane concentration (<1%), and the growth rate was low.

In this work, we applied a high methane concentration (>7%) for n-type doping of single crystal diamond. The growth rate is

about 20 µm/h, and the SIMS results indicate a relative higher P doping concentration . This is the first time in China to

synthesis a n-type single crystal diamond through MPCVD method. The details will be displayed in the meeting.


2018 年 10 月 23-25 日中国·深圳


106

W205-201808131509

Design and Simulation of 1800V 40A 4H-SiC SBD using TCAD

Min Yuan, Houcai Luo, Chunjian Tan, Quan Zhou, Luqi Tao, Huaiyu Ye, and Xianping Chen*

Key Laboratory of Optoelectronic Technology & Systems, Education Ministry of China, Chongqing University and College of

Optoelectronic Engineering, Chongqing University.

400044 Chongqing, China.

[email protected]

Abstract

Silicon carbide (SiC) is presenting as an attractive material for the next generation high voltage power devices which

benefits from its excellent material properties. SiC Schottky barrier diode (SBD) compares with silicon based, which has

superior characteristics in terms of rectification, reverse recovery time, etc. In this paper, a high voltage 4H-SiC SBD with

reverse breakdown voltage of 1800 V and forward current of 40 A is designed as implemented in TCAD. The termination

structure of the device is designed with multiple Field Limiting Rings (FLRs). The parameters of the active area and FLRs

terminal protection structure are optimized. The steady state and transient characteristics of the device are simulated separately.

As a result, the thickness of the N-type epitaxial layer is 16 μm and the doping concentration is 5.8×1015 cm−3. Furthermore, the

forward current is 40 A when the forward voltage is 1.60 V at room temperature. Finally, a temperature generation model is

added to calculate the lattice temperature profile and analysis areas of possible failure during pulsed operation.


2018 年 10 月 23-25 日中国·深圳


107

W205-201808151215

Optimization of Close-Coupled Showerhead suitable for wide bandgap semiconductor production

Wenqing Fang, Chuanbing Xiong, Yong Pu, Li Wang, Jianli Zhang, Junlin Liu, Peng Zhao, Longquan Xi, Zhijue Quan,

Changda Zhen, Xiaolan Wang, Chunlan Mo, Huihua Tang, Shuan Pan, Chaopu Yang, and Fengyi Jiang*

Nanchang University

Nanchang, Jiangxi, P.R.China

[email protected], Mobil: 13807095537

Abstract

This paper summarizes the growth characteristics and mechanism of 4 kinds of Close-Coupled Showerhead(CCS)

developed by our unit in the past 20 years. Based on these mechanism, it can be see that the mechanism of CCS suitable for

InGaN growth is different from that of CCS suitable for AlGaN. Still based on these mechanism, it is explained why TS CCS is

more suitable for the growth of high alumina materials at present. But why should TS CCS be improved to suit the mass

production of wide band gap semiconductor materials in the future? For this aim, a modified TS CCS is introduced which can

be cleaned online by chlorine gas. It is expected that the modification will not only produce higher quality AlN materials , but

also stabilize the initial state of the reactor, thus ensuring the stability of mass production. This paper also deals with the unique

mechanical Mg δ-doping and mechanical pulse growth. These methods are expected to provide a reference for the growth and

doping of other ultra-wide band gap semiconductor materials.

Key words: TS CCS MOCVD, AlN, Clean on line,δ-doping, pulse growth, AlInN, GaN-on-Si


2018 年 10 月 23-25 日中国·深圳


108

W205-201808200248

Crystalline quality improvement of MBE-deposited sp2-BN films by post thermal annealing

F. Liu1, X. Rong1, T. Wang1, B. Sheng1,2, X. Zheng1, S. Sheng1, F. Bertram2, J. Christen2, F. Xu1, B. Shen1, X. Wang1* 1 State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, China

2 Institute of Physics, Otto-von-Guericke-University Magdeburg, Germany

*Corresponding author’s E-mail: [email protected]

Abstract

sp2-BN has attracted tremendous interest over the past decades due to the ultra-wide bandgap and layered structure, and its

promising applications in efficient deep ultraviolet optoelectronics devices [1]. Compared with other III-nitride materials,

sp2-BN exhibits lower acceptor energy level, which provides a new approach to solve the p-type contact bottleneck in traditional

AlGaN-based UV-LEDs. Due to the strong deep ultraviolet exciton emission and large exciton binding energy, sp2-BN is

suitable for realization of high temperature exciton emitting devices [2]. Despite many efforts have been devoted to growth of

sp2-BN epilayer, there are still severe challenges on the crystal quality in non-metallic substrates [3].

In this work, sp2-BN films are grown on sapphire substrates by plasma assisted molecular beam epitaxy (PA-MBE) at

thermocouple temperature of 900℃. The sp2 hybridization of the grown BN has been confirmed by X-ray photoelectron

spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). Precise boron flux modulated process helps in

improving crystalline purity and suppress the formation of AlN due to nitridation of the sapphire substrate. However, it is very

difficult to directly crystalline BN layers, as evidenced by the hollow reflection high energy electron diffraction (RHEED)

pattern during growth and the non-detectable diffraction peaks in X-ray diffraction (XRD) measurement after growth. This is

ascribed to the relatively low temperature in PA-MBE chamber.

In light of this limitation, we then high temperature annealed the as-grown samples in a tubular furnace at 1700℃ under

nitrogen ambient, which is similar as the case of AlN [4]. The BN (002) diffraction peak is observed at 26.6° after thermal

annealing, showing sp2-BN crystallinity. A band gap energy of ~6.0 eV is estimated from absorption spectrum, which agrees

well with the theoretical predicted and previous reported values [5]. In addition, the deep ultraviolet emission at 227 nm is also

identified by low temperature cathodoluminescence (CL) measurement. Our work indicates that post thermal annealing will

significantly improve the crystalline properties of sp2-BN films. The combination of MBE and thermal annealing provides an

alternative way for high quality sp2-BN.

REFERENCES:

[1] K. Watanabe et al., Nature Photonics 3, 591 (2009).

[2] T. Tran et al., Nature nanotechnology 11, 37 (2016).

[3] H. Jiang et al., Semicond. Sci. Technol. 29, 084003 (2014).

[4] H. Miyake et al., Applied physics Express 9, 025501 (2016).

[5] M. Silly et al., Physics Review B 75, 085205 (2007).

https://en.wikipedia.org/wiki/Fourier_transform_infrared_spectroscopy


2018 年 10 月 23-25 日中国·深圳


109

W205-201809041814

Synthesis and application of continuous hexagonal boron nitride films by RF-sputtering

Xiao Qin, Qiang Li, Feng Yun



[email protected]

Abstract

Hexagonal boron nitride (h-BN) is an excellent thermal conductor and a good electric insulator. Meanwhile, the lattice of

h-BN is similar to that of graphene, h-BN is widely used as the substrate and heat-resistant insulating material which is also a

promising material for the deep ultraviolet optoelectronic devices due to its large direct bandgap. Therefore, the preparation of

high-quality h-BN films become an attractive research topic. Due to rigorous growth conditions, it is difficult to synthesize

high-quality and large-size h-BN crystals.

In this work, we deposited h-BN films on different substrates by RF magnetron sputtering. The effects of various parameters,

such as deposition time, gas pressure, deposition temperature, RF-power, bias, and gas flow rate ratio on the growth of h-BN

films were investigated systematically. A good thin film was obtained at the sputtering power of 150W under 500℃. The

obtained film was characterized by scanning electron microscope (SEM), X-ray diffraction, and Raman spectroscopy. The

relationship between film structures and various process parameters were optimized based on the measurement results. And then,

the surface roughness and optical properties of h-BN film were analyzed. Finally, the optimum deposition parameters for h-BN

films with excellent optical properties were proposed.


2018 年 10 月 23-25 日中国·深圳


110

W205-201809051724

Hydrogen-terminated diamond field-effect transistor with YSZ dielectric layers

Yan-Feng Wang, Xiaohui Chang, Wei Wang, Dan Zhao, Jiao Fu, Zongchen Liu, Guoqing Shao, Zhangcheng Liu, Juan Wang,

Yan Liang, Shaopeng Zhang, Shuwei Fan, Renan Bu, Jingwen Zhang, Hong-Xing Wang*

Abstract

Diamond exhibits many outstanding properties such as good light transmittance, effective resistance to radiation damage, large

bandgap, high breakdown voltage, high thermal conductivity, high carrier mobilities etc., making it having potential applications

in the fields of wide range optical transparent window material, coating tools, especially in the field of electron devices which

can work in high frequency, high power, high temperature as well as corrosive environment [1-2]. When diamond is treated by

hydrogen plasma, a two dimension hole gas (2DHG) layer will be formed under diamond surface with a sheet hole density of

1013 cm-2. However, this 2DHG layer is thermally and chemically instable. In order to solve this problem, dielectric layer is

often deposited on H-diamond surface in metal-oxide-semiconductor field effect transistor (MOSFET) field. Up to now, various

dielectric layers have been used in H-diamond MOSFET such as SiO2, Al2O3, HfO2, Ta2O5, and ZrO2 etc.. Yittria-stabilized

zirconia (YSZ) is an excellent dielectric material with high thermal stability, large dielectric constant and band gap of 27 and 5

eV, respectively.

In this work, investigation of H-diamond FETs with YSZ dielectric layer has been carried out. Firstly, gold electrodes were

patterned on H-diamond by electron beam evaporation technique. Secondly, UV-ozone was used to insulate the device. Then,

YSZ dielectric layer was deposited on p-type conduction channels by magnetron sputtering deposition technique. After that, Al

gate was deposited on H-diamond by electron beam evaporation technique. The length and width of channel was 15 and 100

rical properties of this H-diamond MOSFET was investigated. The detail will be presented in the

conference.

Figure. ID-VDS characteristic of H-diamond with YSZ dielectric

[1] H. Kawarada, et al., C-H surface diamond field effect transistors for high temperature (400 °C) and high voltage (500 V)

operation, Applied Physics Letters, 105 (2014) 013510.

[2] Yuya Kitabayashi, et al., Normally-Off C–H Diamond MOSFETs With Partial C–O Channel Achieving 2-kV Breakdown

Voltage, IEEE Electron Device Letters 38 (2017) 3.


2018 年 10 月 23-25 日中国·深圳


111

W205-201809060936

Fabrication of single crystal diamond p-i-n photodiode

Zhangcheng Liu, Dan Zhao, Jin-Ping Ao and Hongxing Wang


No.28, Xianning West Road, Xi’an, China

[email protected]

Abstract

Deep ultraviolet (DUV) photo detection is becoming increasingly important for its variable applications such as flame detection,

engine monitoring, chemical sensing, and intersatellite communications. Among many wide bandgap semiconductor materials

used to fabricate DUV photodetectors, diamond is a promising candidate owning to its high carrier mobility (3800 cm2/Vs for

hole and 4200 cm2/Vs for electron), high thermal conductivity (22 W/cmK), low dielectric constant (~5.7) and high radiation

hardness. Due to the difficulty in n-type doping technique, early diamond photodetectors are mainly metal-semiconductor-metal

photoconductor and single Schottky barrier photodiode. These years, n-type doping in diamond has been successfully performed

by P doping through microwave plasma chemical vapor deposition (MPCVD) method. Since then, diamond p-i-n structure has

been investigated for use as DUV light emitting diodes, X-ray radiation sensors, and power electronic devices. Some works also

apply diamond p-i-n diode for DUV sensor, but the diamond surface is (111) oriented. In fact, (100) diamond is more suitable

for markets and applications. Moreover, the methane concentration for P doping is low (<1%), leading to a low growth rate.

In this work, we fabricated a single crystal (001) diamond p-i-n photodiode for DUV photo detection with a high P doping

growth rate. An intrinsic diamond epitaxial layer was firstly grown on the high-pressure high-temperature boron doped single

crystal diamond substrate through MPCVD method. Then, P-doped diamond film was grown on the intrinsic layer in the same

chamber. To realize a high growth rate, we apply a high methane concentration (>7%). At last, Ti/Au electrodes were patterned

on both sides and annealed for a better ohmic contact. The electrical and optoelectronic properties of the photodiode were

characterized and the details will be presented on the conference.


2018 年 10 月 23-25 日中国·深圳


112

W205-201809070956

Fabrication of Schottky barrier diodes on O-, F-, N-, and Cl-terminated diamond

Dan Zhao, Zhangcheng Liu, Juan Wang, Jiao Fu, and Hongxing Wang


No.28, Xianning West Road, Xi’an, China

[email protected]

Abstract

Diamond is a promising semiconductor for future high-voltage high-temperature applications due to its excellent properties,

such as high breakdown field, wide band-gap and high carrier mobility, etc. This has encouraged researchers to extensively

investigate diamond power devices, such as Schottky barrier diodes (SBDs). etc. Furthermore, the common surface termination

used for fabricating diamond SBDs is oxygen-termination due to its negatively electron affinity. In addition, SBDs with other

surface terminations such as fluorine-, nitrogen-, and chlorine-termination (F-, N-, Cl-termination) also exhibited negatively

electron affinity. However, SBDs fabricated on F-, N-, and Cl-termination have obtained few investigations.

In this work, SBDs fabricated on F-, N-, and Cl-terminated diamond surface have been investigated. High-pressure

high-temperature type IIb (001) substrate in a size of 3×3×0.3 mm3 was used. A thin unintentionally lightly boron-doped

epitaxial layer was grown on substrate by using microwave plasma-enhanced chemical vapor deposition technique.

Subsequently, F-, N-, and Cl-termination was obtained by inductively coupled plasma technique in C4F8, N2, and Cl2

atmosphere, respectively. Then, Ti/Ni/Au were fabricated on the diamond backside followed by annealing at 420 °C for 10 mins

to obtain good ohmic characteristics. Finally, Zr/Ni/Au used as Schottky contact were fabricated on F-, N-, and Cl-terminated

diamond surface, respectively. For comparison, Zr/Ni/Au also fabricated on oxygen-terminated diamond surface. The results

will be presented on the conference.


2018 年 10 月 23-25 日中国·深圳


113

W205-201809071010

Diamond Schottky barrier diodes with floating metal rings for high breakdown voltage

Juan Wang, Dan Zhao, Yanfeng Wang, Zhangcheng Liu, Xiaohui Chang, Jiao Fu, Zongchen Liu, Shaopeng Zhang, Yan Liang,

Hong-Xing Wang*


No.28, Xianning West Road, Xi’an, Shaanxi, P.R. China

[email protected]

Abstract

In the past decades, diamond has gained increasing attention due to its a variety of excellent properties such as wide bandgap

(5.5eV), high breakdown field strength (>10MV/cm), high hole mobility (3800cm2/Vs) and high thermal conductivity

(22W/cm/K), which make it suitable for high power, high frequency and high temperature applications. Diamond Schottky

barrier diodes (SBDs) have been extensively investigated because of their fast switching characteristics and high breakdown

voltages. However, the breakdown voltages of diamond SBDs without any edge termination structures are expected to be lower

than the theoretical values due to the electric field crowding at the edge of devices. In order to reduce the electric field

concentration and suppress the premature breakdown of the main Schottky junction, various edge termination techniques such

as floating guard ring, field plate and floating metal ring (FMR) etc. are proposed. Among these techniques, FMR is the simplest

one because it can be formed simultaneously with the main Schottky junction and does not require additional troublesome

process.

In this work, diamond SBDs with FMRs structure for high breakdown voltage have been fabricated and investigated. Firstly,

CVD single crystal diamond was grown on the IIb-type HPHT diamond substrate. Secondly, oxygen termination surface was

obtained through the ultraviolet ozone treatment. Then, Ti/Ni/Au ohmic contact was performed and annealed in 420℃ for 10

minutes. Lastly, Zr/Ni/Au Schottky contact with FMRs was formed. The three parameters of ring spacing, ring width and ring

numbers were optimized in order to improve the reverse breakdown voltage. The results will be presented at the conference.


2018 年 10 月 23-25 日中国·深圳


114

W205-201809071437

Realization of fast growth of n-type doping single crystal diamond through MPCVD method

Hong-Xing Wang*, Zhangcheng Liu, Fang Lin and Dan Zhao

Institute of Wide Bandgap Semiconductors, Xi’an Jiaotong University, Xi’an, 710049, China

*[email protected]

Abstract

With the development of semiconductor technology, high-power-high-frequency electronic devices have begun to spread

rapidly. Compared with typical semiconductor materials, such as SiC and GaN, diamond has attracted much more attention for

high potential usage in power devices like Schottky barrier diode, metal oxide semiconductor field effect transistors and p-n

junction diode due to its favorable properties such as high breakdown field, high thermal conductivity, high mobility, and low

dielectric constants. However, there exists two main barriers to use diamond. One is the crystal size and quality, another one is

the n-type doping technology. Nitrogen, a common group-V impurity, creates a deep impurity level at 1.7 eV below the bottom

of the conduction band. Another group V element P has been successfully doped in diamond for both (111) and (001) surface

and shows a relatively shallower doping level. Since then, much progress has been achieved. All these works applied a relatively

low methane concentration (<1%), and the growth rate was low.

In this work, we applied a high methane concentration (>7%) for n-type doping of single crystal diamond. The growth rate is

about 20 µm/h, and the SIMS results indicate a relative higher P doping concentration . This is the first time in China to

synthesis a n-type single crystal diamond through MPCVD method. The details will be displayed in the meeting.


2018 年 10 月 23-25 日中国·深圳


115

W205-201809071438

Direct Bonding of Diamond and Si at Toom Temperature by Surface Activated Bonding

Jianbo Liang and Naoteru Shigekawa

Department of Physical Electronics and Informatics, Graduate School of Engineering, Osaka City University, Sugimoto 3-3-138

Sumiyoshi-ku, Osaka 558-8585, Japan


Abstract

Diamond is expected to be the best potential candidate as the next generation semiconductor material for high power and high

frequency electronic devices. However, the cost of diamond is extremely expensive in comparison with Si. If it is possible to

combine single crystal diamond with the large area Si substrate, diamond-based power devices could be fabricated using Si

Large Scale Integrated (LSI) process facilities. The combination of diamond devices and Si LSI with various functions on the

same substrate would be very useful for developing electronics application. In this work, we fabricated diamond/Si bonding

interface at room temperature by surface activated bonding (SAB) and investigated the structures of the bonding interface by

transmission electron microscopy (TEM).

A high-pressure and high-temperature (HPHT) synthetic type-Ib (100) single-crystal diamond with a size of 4 mm × 4 mm ×

0.55 mm was bonded to a n-Si (100) substrate with a size of 15 mm × 25 mm × 0.53 mm by means of SAB. Prior to the

bonding, the diamond chip surface was polished by chemical-mechanical planarization (CMP). The averaged roughness (Ra) of

diamond and Si surfaces were measured to be 0.32 nm and 0.25 nm, respectively by an atomic force microscope (AFM).

The cross-sectional TEM image of Diamond/Si bonding interface is shown in Fig.1. A transition layer with a thickness of

about 20 nm was formed at the interface, which should be amorphous layer because it has no lattice fringes and is distinct from

adjacent Si and Diamond crystalline phase. More importantly, no structural defects such as cracks were observed at the interface.

This result indicated that Si and Diamond were firmly bonded to each other and Diamond/Si bonding interface fabricated by

SAB are applicable for the combination of Diamond-based devices and Si LSI.

Fig. 1 Cross-sectional TEM image of the diamond/Si bonding interface.


2018 年 10 月 23-25 日中国·深圳


116

W205-201809071701

Iridium nanodisks for improved diamond UV photodetector

Xiaohui Chang, Yan-Feng Wang, Zhangcheng Liu, Dan Zhao, Jiao Fu, Xiaofan Zhang, Shuwei Fan, Renan Bu, Jingwen Zhang,

Wei Wang, Hongxing Wang

School of Electronics and Information Engineering, Wide Band Gap Semiconductors, Xi’an Jiaotong University

No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P.R. China

[email protected]

Abstract

Diamond is a promising material for UV photodetector due to its outstanding properties, such as wide band gap (5.5eV), high

thermal conductivity (22W/cm•K), high carrier mobility (electron: 4500 cm2/V•s, hole: 3800cm2/V•s) and high saturation

velocity (1.5X107cm/s). However, as the indirect bandgap semiconductor, diamond leads to significantly lower absorption

coefficients compared to direct wide bandgap materials. Therefore, the responsivity of diamond-based UV photodetectors is

difficult to achieve expected value. Localized surface plasmon resonance (LSPR) can achieve enhancement of localized field

through coupling of incident light and metal nanoarrays. Therefore, increase of responsivity is expected by enhancing optical

absorption of incident photons within the semiconductor region near each nanoparticle. Iridium has many better properties, such

as the most corrosion-resistant, high melting point, high chemical stability, and the most important is that Ir, as a platinum group

metal, has been suggested as an alternative plasmonic material in the UV regions of the spectrum [1].

In this work, a diamond UV photodetector with Ir nanodisks was fabricated on a CVD single crystal diamond film which was

grown on Ib-type HPHT diamond substrate. Firstly, after growth of single crystal diamond film, the surface was changed from

hydrogen termination to oxygen termination through boiling the sample in the acid mixture. Secondly, the ultrathin anodic

aluminum oxide template was transferred to the diamond surface. Thirdly, the 10nm Ir film was deposited on the sample by

using electron beam evaporation technology. Fourthly, the sample was immersed in the boiled acetone solution to remove

ultrathin anodic aluminum oxide template. Finally, Ti/Au electrodes were patterned on the sample surface by electron beam

evaporation technique. The morphologies of Ir nanodisks and the quality of diamond film were investigated. The sample's

photoelectric properties also have been evaluated. The detail will be presented at the conference.

[1] T. Grinys, M. Silinskas, A. Mekys, A. Kalpakovaite, R. Tomasiunas, Self-organization of iridium nanoislands for GaN

applications, physica status solidi (c), 10 (2013) 421-424.


2018 年 10 月 23-25 日中国·深圳


117

W205-201809091146

Single crystal growth and characterization of β-Ga2O3

Wenxiang Mu, Zhitai Jia, Bo Fu, Xutang Tao

Institute of Crystal Materials, Shandong University

Shandong University, Shanda nanlu 27, Jinan, 250100, China

[email protected]

Abstract

As a wide-bandgap semiconductor with the bandgap of 4.8 eV, β-Ga2O3 is attracting more and more attention in recent years,

because it has a lot of new applications include: deep ultraviolet photodetectors, light-emitting diodes (LEDs), Schottky diodes,

high voltage transistors and high temperature gas sensors. Its transparency from deep ultra violet (DUV) to infrared (IR) region

offers opportunities for designing a novel optoelectronic devices operating at shorter wavelengths. Meanwhile, β-Ga2O3 has

potential for high-voltage power devices with higher breakdown voltage than GaN and SiC. Our objective is to grow high

quality and large size β-Ga2O3 single crystals and develop its potential applications.

We have chosen the EFG method to grow the β-Ga2O3 single crystal, since it is convenient for the growth of high quality

β-Ga2O3 single crystals. In this method the Ir-particles, floating on the surface of the melt, do not disturb the growth process and

the solid-liquid interface is stable. Crystals can be pulled up at a higher speed, 10-30mm/h, with comparatively lower energy

consumption than Cz method. However, until now there is no detailed works reported about the controlling of the temperature

gradient near the top of the Ir die, crystal crack, Ga2O3 raw material decomposition and volatilization, and the Ir crucible erosion,

during the crystal growth process.

In this work, we have grown colorless β-Ga2O3 single crystal by the EFG method along different directions. Especially we have

checked the possible ways, like the growing atmosphere, the temperature gradient, and so on, to reduce the decomposition of

Ga2O3 at high temperature and to protect the iridium crucible. The grown crystal has been checked by the high resolution X-ray

diffraction, and the FWHM was 36.5 arcsec, which showed good crystal quality. Furthermore, the basic physical properties have

been systematically studied.


2018 年 10 月 23-25 日中国·深圳


118

W205-201809091951

A review of different type defects in β-Ga2O3 single crystals and their effects on device performance

Bo Fu, Zhitai Jia, Wenxiang Mu, Yanru Yin, Jian Zhang, Xutang Tao

State Key Laboratory of Crystal Materials & Key Laboratory of Functional Crystal Materials and Device, Shandong University

Jinan 250100, China

[email protected]

Abstract

β-Ga2O3, as a Wide-bandgap semiconductor (WBG), is expected to be applied to power electronics and solar blind UV

photodetectors. Here, the defects in β-Ga2O3 single crystals are summarized in detail. Four type of defects were found: (1)

dislocations, (2) voids, (3) twin, and (4) small defects. The dislocations and the surrounding regions can act as paths for the

leakage current of SBD in single crystals. Not all voids produced the leakage current. It was not confirmed that whether small

defects affected the electrical properties using the etch-pitting method or not. In addition, doping impurity was not related to the

leakage current definitely. Most of small defects were induced by

mechanical damage. The screw dislocation was originated form a subgrain boundary. The edge dislocation lying on a plane

slightly tilted from the (102) plane, a possible slip plane was the (101) plane. The voids defect, including hollow nanopipes,

PNPs, NSGs, line-shaped grooves, maybe be caused by the condensation of excess oxygen vacancies, the penetration of tiny

bubbles or local meltback. The nucleation of twin lamellae was formed at the growing stage of the “shoulder part”.


2018 年 10 月 23-25 日中国·深圳


119

W205-201809291307

Temperature-dependent electrical properties of a Pt/(100) β-Ga2O3 Schottky diode within barrier

inhomogeneity

GuangZhong Jian, QiMing He, WenXiang Mu, Bo Fu, Hang Dong, Yuan Qin, Ying Zhang, HuiWen Xue, ShiBing Long,

ZhiTai Jia, HangBing Lv, Qi Liu, XuTang Tao, Ming Liu

Institute of Microelectronics of Chinese Academy of Sciences

No.3, BeiTuCheng West Road, ChaoYang District, Beijing, China, 100029

[email protected]

Abstract

β-Ga2O3 has emerged as a potential semiconductor for power device applications, considering its ultra-wide bandgap

(4.7-4.9eV). To analyze the temperature-dependent characteristics of schottky contact between β-Ga2O3 and metal platinum (Pt),

We fabricated a Pt/β-Ga2O3 schottky barrier diode (SBD) and tested its electrical properties within a linear temperature range. A

low on-resistance of 3.3mΩ⋅cm2 and high forward current density of 73.6A⋅cm-2 were measured at room temperature. Forward

current-voltage curves presented a clear ascendable trend with rising temperatures and all parameters were derived within

thermionic emission theory. Our results indicated an ideality factor of 2.57 and a zero-bias barrier height of 0.47eV at 125K

respectively, while a more ideal value of 1.16 and a higher value of 1.00eV were obtained at 350K. This phenomenon was in

coincidence with the prediction of Schottky barrier inhomogeneity and the Gaussian distribution of barrier heights was assumed

to analyze the temperature dependent parameters. Based on this assumption, the mean barrier height of 1.27eV and zero-bias

standard deviation of 0.13eV were obtained. The conventional Richardson plot gave a much lower value of the Richardson

constant compared with its theoretical value of 41.11 A⋅cm-2⋅K-2. In contrast, a modified Richardson constant of 36.02

A⋅cm-2⋅K-2 was derived under the assumption of Gaussian distribution. Capacitance-voltage analysis results showed almost

constant values of barrier height, which was different from current-voltage analysis results. This difference could also be

explained by the Gaussian distribution of barrier heights. Physical image with accurate expressions was obtained, which

described the barrier height between metal Pt and β-Ga2O3 varying versus temperature and applied bias.


2018 年 10 月 23-25 日中国·深圳


120

W205-201809292150

I-V Characteristics and Electronic Field Simulation of Enhance-Mode Ga2O3 MOSFETs Using

Silvaco-TACD

Xuanze Zhou, Yangtong Yu, Hang Dong, Qiming He, Yuan Qin, Guangzhong Jian, Ying Zhang, Wenhao Xiong, Xiaohu

Hou,Wei Guo, Shibing Long, Ming Liu

University of Science and Technology of China

HuangShan Road, Hefei,Anhui, 230022, China

[email protected]

Abstract

In this letter, the enhancement-mode β-Ga2O3 MOSFETs with gate trench are simulated by Silvaco-TACD. In order to adjust the

electrical field accumulation at the bottom of gate, MOSFETs with GFP and SFP are designed. The output curve,transfer curve

and electric field distribution of the device are obtain through simulation. The simulation result shows that the SFP and the GFP

can effectively adjust the peak electric filed in the dielectric layer,compared with the structure without field plate which has the

same size.However,the SFP and the GFP structure doesnt work obviously until their have some certain length,neither too long

nor too short. This structure works superiorly at high voltages compared to low voltages.


2018 年 10 月 23-25 日中国·深圳


121

W205-201809292218

Electrical Characteristics of Enhance-Mode Ga2O3 MOSFETs with gate trench

Hang Dong, Qiming He, Yuan Qin, Guangzhong Jian, Ying Zhang, Xuanze Zhou, Yangtong Yu, Wenhao Xiong, Xiaohu Hou,

Wei Guo, Shibing Long, Ming Liu

Institute of microelectronics, Chinese Academy of Sciences

Beitucheng West Road, Bei Jing,100029, China

[email protected]

Abstract

In this letter, enhance-mode MOSFET with gate trench is fabricated on 200 nm high doping β-Ga2O3 layer, which is

homoeptaxially grown by MBE. In these devices with different sizes, 30 nm Al2O3 is used as gate dielectrics and 100 nm SiO2

is passivation layer . Though electrical measurement, we obtain its transfer curve and output curve. The performance parameters

like threshold voltage, on/off ratio, saturation drain-source current, subthreshold ampltude etc, are also extracted. What's more,

in order to confirm the property of gate etching, we obtain imterface state density at the bottom of gate trench through high-low

frequency C-V method. In addition, short-channel effect is observed in devices with 2 um gate lenght.

To sum up, we successfully fabricate E-mode MOSFET on Ga2O3, and take some basic test.


2018 年 10 月 23-25 日中国·深圳


122

SW206-201810131335

AlGaN MOCVD Simulation for Growth Optimization and Reactor Design

Kazuhiro Ohkawa

Computer, Electrical and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology

(KAUST), Thuwal, Saudi Arabia

Abstract

Low-pressure for AlGaN MOVPE growth is generally adopted. At atmospheric pressure, its growth rate goes down

significantly. In this paper, we will report on successful AlGaN growth simulation in the wide ranges of pressure, Al/(Ga+Al)

ratio, and temperature. Growth rates and compositions of AlGaN in the simulations are in good agreement with those in the

experiments by considering proper polymer formation.

One of the key parameters in chemical reactions is temperature. We have calculated the temperature distributions in an

MOVPE system by considering the optical properties of sapphire and quartz at high temperatures [1]. Based on the realistic

simulation of temperature distribution in the gas phase and surfaces of reactor wall and substrates, we have developed GaN and

AlN growth simulations in TMGa/NH3/H2 and TMAl/NH3/H2 systems, respectively [2, 3]. The code for simulation is

CFD-ACE+ using our original nitride MOVPE parameters. The parameters are available from Wave Front Ltd, Japan [4]. We

used a Taiyo-Nippon Sanso MOVPE system for the experiments.

Using the previous AlN and GaN simulations, we could find out the possible additional polymer formation among Al-

and Ga-related molecules. Decomposition of molecules at a specific temperature causes further polymer formation. In the case

of TMAl/TMGa/NH3/H2 system, such crucial decomposed molecules are MMAl-NH, Al-N, and Ga-N, here MM is a

mono-methyl group. These decomposed molecules form polymers such as [MMAl-NH]n-[Ga-N]m,

[MMAl-NH]n-[Ga-N]m-[Al-N]k, and [Al-N]n-[Ga-N]m (k, m, and n are 1-6). The pressure dependences of the AlGaN growth

rate and its Al content in simulations are good agreement with those in experiments. Without consideration of the proper

polymer formation, it is impossible to realize such good agreement. Also, the MOVPE growth of AlGaN is sensitive to

temperature and the ratio of TMAl/ (TMAl + TMGa). We will explain these dependencies at the conference.

This technology makes us possible to optimize nitride MOCVD and design its upgraded reactors.

REFERENCES:

[1] A. Hirako, and K. Ohkawa, J. Cryst. Growth 276, 57 (2005).

[2] A. Hirako, K. Kusakabe, and K. Ohkawa, Jpn. J. Appl. Phys. 44, 874 (2005).

[3] T. Uchida, K. Kusakabe, and K. Ohkawa, J. Cryst. Growth 304, 133 (2007).

[4] http://www.wavefront.co.jp/CAE/MOVPE-database/


2018 年 10 月 23-25 日中国·深圳


123

SW206-201810091126

3D Numerical Simulation on HVPE Chambers for the Growth of 6-inch GaN substrates

Lin CHEN, Xiangqian XIU, Yuxia ZHU, Xuemei HUA, Zili XIE, Rong ZHANG, Youdou ZHENG

Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing

University, Nanjing, 210023, Jiangsu, P. R. China

Abstract

The demand for high-quality, large area and low cost GaN substrates is becoming increasingly urgent in order to improve

the performance of wide band gap optoelectronic devices and reduce production costs. Halide vapor phase epitaxy (HVPE) is

widely used in the preparation of free-standing GaN substrates in recent years. In this work, the CFD method was used to

simulate the growth chamber of the 6-inch HVPE system in three dimensions to optimize equipment design. Numerical analysis

was carried out on the key geometric parameters of the tube, reaction pressure and the effect of substrate rotation. The

uniformity of growth rate was optimized through redistribution of the source gases V/III ratio above the substrate by changing

geometric parameters. And the streamline arrangement was adjusted by changing the rotational speed to eliminate the vortex and

improve the growth quality. In addition, the optimized parameters for suppressing parasitic deposition and improving the quality

of epitaxial films were obtained by analyzing the addition of extra HCl.


2018 年 10 月 23-25 日中国·深圳


124

SW207-201810110927

Semiconductor Batch Performance in Terms of Bath Tub Curve Types and Similarity Index

R. Ross

IWO Institute for Science and Development, Ede, Netherlands & Delft University of Technology, Delft, Netherlands

Abstract

The present report addresses reliability aspects that are related to the product development and comparison under various types

of ageing and (accelerated) testing. Furthermore how does this affect a system and how to compare batches. After a brief

overview of relevant functions (cumulative distribution F, distribution density f and hazard rate h) and distributions (Normal,

Lognormal, Weibull and exponential) with their meaning and applications, particular attention is paid to three subjects: the early

failures (also called infant mortality); the effect of small test series and to the issue of comparing statistical distributions.

As for the first topic about early failures, it is discussed that a wide spread practice is to use the Weibull distribution for

describing the three regions of early failures (infant mortality), random failure and wear-out failure. If the Weibull distribution

applies, then the so-called shape parameter β is often used to discriminate the three regions as follows. If β<1, then the hazard

declines with increasing time t, which is characteristic for an infant mortality process; if β>1 the hazard rate grows with

increasing time which is typical for a wear-out process and finally if β=1 then the hazard rate is constant which means neither

infant mortality nor wear-out, which is typical for a random failure process. From this stage on various widely spread

misconceptions exist. The usually shown bath tub curve (Fig.1) is a sum of three hazard rates (namely with β<1, β=1 and β>1)

which applies that all three processes are active in all semiconductors simultaneously. Commonly, the infant mortality is

explained as due to some early failing products with manufacturing defects as a subgroup in the total batch. However a

subgroup implies that not all processes are active simultaneously in all objects and another bath tub appears to apply. The

subgroup itself is a weak set of products that fails early most probably due to fast wear-out. It is not about a β<1 but rather a

scale p

with its consequences.

Fig. 1 Bath tub curve as sum of three processes active in all products Fig. 2 Bath tub curve as sum of two subgroups

The second issue is about small test sets. If these are analyzed with Weibull statistics, then systematics errors occur that

generally make the products look better than they actually are (even with non-censored data). This phenomenon is called biasing

and increases with a decreasing number of test samples. The effect is also very relevant when test series are compared that have

different sizes. Fortunately such biases can be corrected for with convenient formulae based on a power function as is discussed.

The third issue is about comparing different failure distributions. The question to be answered is to what extent the behavior of

two products batches is the same. For instance the observed distribution f(t) of the failure behavior of a produced batch should

follow a reference distribution g(t), but how similar are observed f(t) and reference g(t)? A conventional technique is the

chi-squared method, however this method assumes the ruling distribution to be the Gauss or Normal distribution, whereas

ageing is usually Weibull or a combination of distributions. Fairly recently the similarity index S(t1,t2) is used to characterize to

what extent two distributions are the same (i.e. are similar). Here t1 and t2 are the start and end of a time interval (e.g. t1=0 and

t2→∞) where the similarity is evaluated. This index S(t1,t2) reaches value 1 if the two distributions are fully similar and 0 if

they have nothing in common. It can compare different and complex distributions. The expression of the similarity index is:

It can be used to compare product batches (including observed and reference). It can also be used to predict the size of an early

failing subgroup with a regular product group. It can also be used to evaluate how similar standard ageing and accelerated

ageing are. Its meaning and use are further explained in the presentation.


2018 年 10 月 23-25 日中国·深圳


125

SW206-201808151038

3D CFD Simulation of High-temperature MOCVD Reactor for Epitaxial AlN Growth

JK. Yang1*, JC. Yan1,2,3, XD. Wang2,3, H. Chen2,3, H. Li2,3, WJ Wang1,2,3, RF. Duan1,2,3, JX. Wang1,2,3, YP. Zeng1,2,3, JM. Li1,2,3

1State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, No. 35,

Tsinghua East Road, Haidian District, Beijing 2Youwill Hitech Co. Ltd, No. 35, Tsinghua East Road, Haidian District, Beijing

3 Advanced Ultroviolet Optoelectronics Co. Ltd, high tech Zone Zhang Ze new industrial park, Changzhi, Shanxi


Abstract

Multi-wafer MOCVD equipment for epitaxial AlN growth is indispensable for the development of AlGaN-based UV LED.

In this study, 3-Dimensional computational fluid dynamics modeling coupling surface reaction kinetics was carried out, and the

number and distribution of the nozzle was optimized for home-made six-wafer reactor chamber. The average growth rate and

inhomogeneity in thickness was about 1μmph and less than 7%, respectively.


2018 年 10 月 23-25 日中国·深圳


126

SW206-201808302336

Gas phase and surface reaction mechanism of AlN MOCVD by quantum chemistry calculations

Ran Zuo, Hong Zhang, Zhou Zhang, Nannan Niu

Jiangsu University

Zhenjiang, Jiangsu, China

[email protected]

Abstract

AlN is one of the most important III-V semiconductors. Among the III nitrides (AlN, GaN and InN), AlN has the widest band

gap, low lattice mismatch and thermal mismatch with GaN, and the strongest metal-nitrogen bond. It is especially suitable for

making UV/deep UV photoelectronic devices, and the buffer and transition layers for GaN-based power electronic

heterojunctions. Because of the strong coordination bond between Al and N, the gas-phase parasitic reaction is strong and the

surface mobility is poor in the AlN MOCVD, which cause the low growth rate, low growth efficiency, and the often poor film

quality. At present, the difficulty in AlN epitaxial growth has become a bottleneck for restricting the application of AlN related

devices. The better understanding of the gas phase and surface reaction mechanism of AlN MOCVD is essential to improving

the growth process and film quality.

In this presentation, we report our study on the gas phase and surface reaction mechanism of AlN MOCVD by using density

functional theory (DFT) of quantum chemistry. In the gas phase reaction, three reaction pathways are known: direct pyrolysis of

TMAl, hydrogenolysis of TMAl with H2, and the adduct-amide formation and polymerization of TMAl with NH3. We will find

the conditions favored by each of the reaction pathways, including the reactor geometry and process parameters, determine the

main precursors for surface reactions, and find the conditions for the nanoparticle formation. The surface reactions of

AlN-MOCVD are still largely unknown. We will study the adsorption and diffusion of major Al-containing particles on the AlN

surface, including MMAl which contains only Al-C bonds, and amides DMAlNH2 and Al(NH2)3 which contain Al-N cores,

and compare the adsorption structures, adsorption energies and diffusion barriers of various surface particles under different

surface conditions (ideal or non-ideal). We also try to determine the optimum conditions for the 2-D step growth, with the

relations of the surface morphology, surface coverage and the gas phase conditions.


2018 年 10 月 23-25 日中国·深圳


127

SW207-201809280931

Packaging and thermal management of quantum dots-converted white light-emitting diodes

Xiaobing Luo

Huazhong University of Science and Technology

Luoyu Road 1037, Wuhan, China

Abstract

Over the past two decades, white light-emitting diodes (WLEDs) based on semiconductor quantum dots (QDs) have been

attracting numerous attentions due to their high luminous efficiency, excellent color rendering index (CRI) and flexible spectral

tuning property. However, the less-than-one quantum efficiency inevitably gives rise to a non-negligible heat generation

problem, which induces high-temperature quenching issues of the QDs and severely hinders their potential applications in

lighting and display industry. Traditional thermal-conductivity-enhancement materials, such as graphene, carbon nanotube and

metals, cannot be used for the thermal management of QDs-WLEDs since they are light-absorbing materials, leading to serious

optical energy loss. In this keynote, some package-inside thermal management (PITM) strategies were proposed to enhance the

heat removal for QDs inside the LED packaging, and retain the luminous efficiency simultaneously, thus reducing the QDs’

working temperature and prolonging their long-term stability.


2018 年 10 月 23-25 日中国·深圳


128

SW207-201807231618

Establishing thermal model for the design of the high-power LED headlight cooling device

Haiyang Wang, Peipei Wang, Jialin Liu and Daxi Xiong*.

Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences.

No.88 Keling Street, Suzhou 215163, China.

[email protected], 0512-69588302.

Abstract

A study of the thermal performance of a novel radiator in high-power LED (light-emitting diode) headlight is presented. The

thermal resistance model is built to analyze the factors which have impacts on the radiator temperature. The analyses are based

on the experiment combined with computations using the CFD software ANSYS Icepak. The prediction results are validated

with the experimental one. The temperature distribution of the LED module and radiator are obtained. The maximum

temperature of the radiator is reduced by about 25℃ compared with a certain headlight while the input power is 16 W. The

effects of the number of fins, substrate spacing and fin thickness on the radiator temperature are also examined. The Results

indicate that the optimum parameters are: number of fins=36, substrate spacing=3 mm and fin thickness=2.5°. Meanwhile, as

the input power increases to 22 W, the maximum temperature of the chip is only 85.01 ℃, therefore, the heat dissipation of

headlight designed in this paper is greatly enhanced.


2018 年 10 月 23-25 日中国·深圳


129

SW207-201808152018

Properties of Thermal Interface Materials and Its Impact on Thermal Dissipation and Reliability of

LED Automotive Lighting

Ru Li1,2, Qian Liu1, Limin Huang2, Liwei Yin2, Guojian Song2

1. Shanghai Institute of Ceramic, Chinese Academy of Sciences. No. 1295, Dingxi Road, Shanghai, China.

2. Changzhou Xingyu Automotive Lighting Systems Co., Ltd. No.182, Qinling Road, Xinbei District, Changzhou, Jiangsu,

China.

E-mail: [email protected], Tel: +86-519-8168-5954, +86-136-8525-5096.

Abstract

The properties of thermal interface materials (TIMs), such as thermal resistance, oil bleed and long term reliability, etc.,

were investigated systematically in the present paper. And their impacts on LED (Light Emitting Diode) automotive lighting

performance were also discussed at the same time. The results shown that different TIMs possess small difference in thermal

resistance and temperature test results. All TIMs were tested by thermal resistance test instrument （T3ster） at 0.1mm thickness

with a typical LED of 18.2W, the smallest thermal resistance is 0.1303K/W, while the highest thermal resistance is 0.2883K/W.

Without using thermal interface material, the thermal resistance is about 0.99K/W, which refers to the thermal resistance of air.

For other properties, such as oil bleed, long term reliability, etc., are also need to be considered comprehensively when it’s used

for LED automotive lighting.


2018 年 10 月 23-25 日中国·深圳


130

SW207-201809031206

ESD Considerations in LED L2 Design

Guoqiao Tao(*), and William van Driel

Signify, High Tech Campus 45, Eindhoven, the Netherlands


Abstract

LED L2 products can be sensitive to Electro-Static Discharge (ESD) events, which may induce latent damages to the LED chip,

causing reliability issues of the product. This paper discusses the mechanisms of ESD events, their effects at chip level, package

level, and board level. Simulations and measurements are carried out to help the understanding. Such in-depth understanding

will help in finding effective ways to protect the product from ESD damage.


2018 年 10 月 23-25 日中国·深圳


131

SW207-201809072239

Threshold Voltage Instability (PBTI) of GaN-based recessed MOS-HEMTs with Fast-IV-Sweep

Method

Qing Zhu, Lixiang Chen, Bin Hou, Mei Wu, Xiaohua Ma and Yue Hao

Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices,

Xidian University, Xi’an 710071, China


Abstract

Fast-IV-sweep method was used to investigate the threshold voltage stability under positive gate stress, with the range of stress

time from 1μs to 1000s, which is more accuracy for GaN-based recessed MOS HEMTs. Typical DC stress was also measured as

comparison. ΔVTH is caused by traps with a broad distribution of trapping and emission time constants, which is relate to traps

at the Al2O3/GaN interface and traps in the bulk of Al2O3 near the interface.


2018 年 10 月 23-25 日中国·深圳


132

SW207-201809111118

Design and fabrication of a thermal mechanical test chip for package reliability assessments

Mian TAO, S. W. Ricky LEE

Hong Kong University of Science and Technology

[email protected]

Abstract

Reliability of an electronic device has always been considered as one of the most important issues. Currently, the increasing of

chip size and power consumption is challenging the package reliability. Flip-chip ball grid array (FC-BGA) with a heat

spreading lid is the most common package for its smaller footprint area and thinner thickness, nevertheless, such type of

package is more vulnerable to thermal stress induced by mismatch of thermal expansion coefficients of different materials in an

elevated temperature. In fact, the root cause in most failure scenario is very likely due to overstress of thermal or mechanical

loading. Furthermore, the thermal and mechanical loading always couple together exacerbating the reliability problem.

Therefore, estimating the thermal-mechanical coupling behavior is critical for a success electronic package.

Performing the reliability test using a fully functioning chip is usually unrealistic, hence, dummy test chips are often employed

in order to reduce the cost of tests and the length of experiment period. People often utilize daisy chain structure to detect

interconnection failure during different mechanical loading tests. Meanwhile, thermal test chips are introduced to estimate the

package thermal performance. However, because of the coupling behavior of thermal and mechanical stress, it is not justified to

assess the package reliability by solely characterizing the thermal behavior or the mechanical. Both of the thermal

characterization and mechanical characterization should be performed simultaneously.

In order address this problem, we design and fabricate a dummy test chip combining daisy chain structure and metal sheet

resistor for heating and temperature sensing together. Layer structures are fabricated on a silicon wafer with polymer dielectric

layers. Copper bonding pads are fabricated for ball grid array interconnection. The test chip is then bonded to a bismaleimide

triazine (BT) substrate and a heat spreading lid is attached to the chip by different thermal interface material so as to complete a

functional test vehicle. Thermal cycling test is conducted on these test vehicles and the thermal resistance of the package is

measured by MentorGraphic T3Ster system at different cycles. The daisy chain connection is being monitored during the

thermal cycling test to detect any potential structural failure.


2018 年 10 月 23-25 日中国·深圳


133

SW207-201809171511

Analysis of pulse-driven LED junction temperature and its reliability

Nick Yang, Brian Shieh, Trio Zeng, Ricky Lee

HKUST LED-FPD Technology R&D Center at Foshan

7-304, Block A, Hantian Ind. Park, Nanhai, Foshan, Guangdong, China

[email protected]

Abstract

LEDs need to be strobed at some higher pulsed current whenever high light output for a short duration is necessary. It is known

the higher pulse current induces the more localized current crowding with overheating and lead to thermal runaway, and

eventually can lead to an early catastrophic damage. While LEDs are capable of withstanding current transients well above the

maximum rated continuous current, there are physical limits that must not be exceeded in order to avoid electrical over-stress.

Operation of LEDs in a continuous pulsed mode at higher levels is possible, but there are trade-offs that may adversely affect

efficacy, chromaticity and reliability. In this paper, the correlation between LED light output degradation and the pulsed junction

temperature due to the high pulsed current at various strobing frequency, strobing duty and peak currents density is investigated

to evaluate its long-term reliability in a continuous pulsed mode at higher levels.


2018 年 10 月 23-25 日中国·深圳


134

SW208-201810031212

Flexible micro-LED displays through heterogeneous integration of thin-film transistors and III-V

optoelectronic devices

William S. Wong

Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario, Canada,

[email protected]

Abstract

The emerging display technology made on gallium nitride (GaN)-based micro light-emitting-diodes (micro-LEDs) promises to

enable the next-generation of emissive displays having high brightness, lowpower consumption, and high resolution compared

to existing display technologies based on organic light-emitting-diodes (OLEDs). In addition to these improvements over OLED

displays, the integration of micro-LEDs with thin-film transistor (TFT) devices provides new pathways for high-brightness and

high-resolution flexible displays.

A promising approach to integrate these disparate materials systems and devices is through optimization of the transistors and

light-emitter devices followed by layer transfer techniques to combine the integrated devices onto a flexible platform.

InGaN-based micro-LED were fabricated on sapphire using a single-mask etching process to define an 8 x 8 array of

micro-LEDs over a 4 mm x 4 mm area. The individual micro-LEDs were 150 um x 150 um in size and had an on-voltage of 2.5

V with a resulting drive current of 5 uA. The micro-LED array was transfered onto a polyethylene terephthalate (PET) substrate

using a laser-liftoff and a low temperature bonding process. Following the micro-LED integration onto PET, inverted-staggered

hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) were fabricated at 170⁰C adjacent to the micro-LEDs to

form a pixel circuit on the PET substrate to create an array having a resolution of 50 ppi. This configuration potentially provides

higher dynamic range and reduced data voltage compared to a conventional emissive-display pixel-circuits. Using a supply

voltage of 20 V and a data voltage between 4 V to 16 V enabled a maximum 90 µA drive current to each micro-LED pixel with

a refresh rate of 60 Hz. With this design, individual pixels were addressed within the array, demonstrating the feasibility of

combining disparate thin-film technologies to create novel flexible circuits for flexible display applications. The performance

parameters under various bending circumstances will be reported to demonstrate the reliability of the flexible micro-LED array.


2018 年 10 月 23-25 日中国·深圳


135

SW208-201809171055

Novel micro scale LED for full color micro display

Hao-Chung KUO

National Chiao Tung University

1001 University Road, Hsinchu, Taiwan 300, ROC

[email protected]

Abstract

We have studied a novel micro scale nano-ring (NR) LED. First, by changing the wall width of the NR LED, the luminescence

wavelength can be changed from 480 nm blue lightto 535 nm green light. Then,we spraythe red quantum dot (QD) material on

the blue NR LED to achieve color conversion. Finally, RGB full color microdisplay can be realized on the same substrate.

We have also improved the luminous efficiency of NR LEDs and the color conversion efficiency of QD materials. In order to

improve the luminous efficiency of NR LEDs, we use the atomic layer deposition (ALD) technique to deposit Al2O3 layers of

different thickness on the sidewall of NR LEDs. By comparison, the optimized ALD layer thickness and the NR LED chip with

the highest luminous efficiency can be obtained. Moreover, in order to increase the color conversion efficiency of QD materials,

we use high-precision QD spraying technology to eliminate the crosstalk phenomenon of QD deposition between adjacent pixels,

and develop DBR reflectors to recycle the excitation light. The QD material is directly contacted with the quantum well of the

NR LED chip. Therefore, the color conversion efficiency of QDcan be further improved by the non-radiative energy transfer

phenomenon.


2018 年 10 月 23-25 日中国·深圳


136

SW208-201809281741

Hybrid nitride-based micro/nano-LEDs with quantum dots for high performance white emission

Zhe Zhuang, Bin Liu, Tao Tao, Peng Chen, Dunjun Chen, Zili Xie, Haixiong Ge, Xiaoyong Wang, Hai Lu, Rong Zhang,

Youdou Zheng

School of Electronic Science and Engineering, Nanjing University

Electronic Engineering Building, Xian Lin Da Dao 163, Nanjing, China

[email protected]

Abstract

An excellent hybrid III-nitride/quantum dots micro/nano-structured light-emitting diode (LED) has been developed between

violet/blue emitting InGaN/GaN multiple quantum wells (MQWs) and various wavelength emitting II-VI quantum dots (QDs)

as color conversion mediums. InGaN/GaN MQWs are fabricated into micro/nano-holes by soft nanoimprint lithography or UV

optical lithography to fill with QDs. A significant reduction in the decay lifetime of excitons in the MQWs of the hybrid

structure has been observed as a result of the förster nonradiative resonant energy transfer (NRET) from the nitride emitter to

QDs. A series of hybrid complementary color LEDs have been demonstrated with a high color rendering index, up to 86,

covering the white light emission at different correlated color temperatures ranging from 2629 to 10000 K, corresponding to

warm white, natural white, and cold white. The efficiency droop of hybrid LEDs was validly suppressed, which mainly resulted

from the extraction of excess carrier concentrations in InGaN/GaN MQWs via the rapid NRET process under the higher

injection condition. It reveals that the novel hybrid micro/nano-LEDs have a great potential to realize efficient and quality white

light emitters.


2018 年 10 月 23-25 日中国·深圳


137

SW208-201809121509

Micro-LED displays: Benefits and Issues of the Monolithic Approach

Kei May Lau

Fang Professor of Engineering and Chair Professor

Department of Electronic and Computer Engineering,

Hong Kong University of Science and Technology,

Clear Water Bay, Kowloon, Hong Kong

Abstract

Mature LED technologies for large area LED displays and general lighting are now commonplaces. The use of LED in

micro-displays is attracting more attention recently, for direct view or projection applications. LEDs have advantages in terms

of efficiency, brightness, lifetime, temperature stability and robustness, compared with other existing micro-display technologies.

The most significant is visibility under bright day-light.

We have reported the fabrication of high resolution truly monolithic micro-display with decent visual quality. We have

developed two different approaches to illustrate high resolution micro-displays with excellent bonding yield. A 1700 pixel per

inch (PPI) passive-matrix and a 400 × 240 active-matrix micro-LED arrays bonded on ASIC have been demonstrated.

Realization of full color LED micro-display remains the biggest challenge because it is not practical to selectively grow three

different epi-layers emitting at different wavelengths on a single substrate for three primary colors. Dedicated for projection

display application, we demonstrated a novel 3LED light engine that can project full color video on screen. 3LED consists of a

trichroic prism that combines RGB images generated from three LED micro-displays based on AlGaInP (Red) and GaN (Green

and Blue) materials. For near-to-eye display application, RGB quantum dots were printed on micro-LED array by aerosol jet

printing, achieving full color LED micro-displays with high image quality.

To maximize the throughput and minimize the light-guiding effect of the transparent sapphire substrate, we use LED epilayers

grown on Si substrates that can be removed using a simple and low-cost SF6-based RIE etching process. Moreover, Si has been

used for GaN growth for over two decades due to its low cost and large scale. In this talk, we report an AMLED micro-display

system consisted of a 64×36 micro-LEDs array using GaN-on-Si epilayers and a CMOS driver.

Bio

Professor Kei May Lau is the Fang Professor of Engineering at the Hong Kong University of Science and Technology (HKUST).

She received the B.S. and M.S. degrees in physics from the University of Minnesota, Minneapolis, and the Ph.D. degree in

Electrical Engineering from Rice University, Houston, Texas. She was on the ECE faculty at the University of

Massachusetts/Amherst and initiated MOCVD, compound semiconductor materials and devices programs. Since the fall of 2000,

she has been with the ECE Department at HKUST. She established the Photonics Technology Center for R&D effort in III-V

materials, optoelectronic, high power, and high-speed devices. Professor Lau is a Fellow of the IEEE (2001), a recipient of the

US National Science Foundation (NSF) Faculty Awards for Women (FAW) Scientists and Engineers (1991), Croucher Senior

Research Fellowship (2008), and the IEEE Photonics Society Aron Kressel Award (2017). She is an Editor of the IEEE EDL and

a former Associate Editor of Applied Physics Letters and Journal of Crystal Growth.


2018 年 10 月 23-25 日中国·深圳


138

SW208-201807291536

Surface distribution of photo-thermal properties of light-emitting devices/arrays based on

micro-hyperspectral imaging technique

Yijun Lu, Lili Zheng, Jian Jin, Yulin Gao, Yue Lin, Ziquan Guo, Zhong Chen

Xiamen University

Room 330, Physics Building, Haiyun Campus of Xiamen University, Xiamen, Fujian, China

[email protected]

Abstract

Micro-hyperspectral imaging technique (MHI) combines hyperspectral and microscope techniques, enables to obtain cubic data

of testing objects, which contain 2D geometric space and 1D spectral information and have merits of both high spatial and high

spectral resolutions. The MHI is an ideal tool for testing surface spectral distribution of micro-light emitting devices/arrays.

Based on MHI, we developed 2D photo-thermal distribution measurement technique for micro-light emitting devices/arrays. A

standard radiant lamp including tungsten lamp and small integrating sphere is used to calibrate the radiant spectra of the MHI

system. We tested the radiant spectra of each pixel of OLED and MicroLED, and derived the surface distribution of luminance

and colorimetrics. Furthermore, We tested the surface 2D temperature distribution of LED by MHI according to the linear

relationship between centroid wavelength and temperature. A 2D function matrix for the centroid wavelength and temperature

relationship is calibrated and obtained by voltage/current pulse signal. Then the surface 2D temperature distribution of LED

under each working condition can be derived by the 2D function matrix. The 2D photo-thermal distribution measurement

technique by MHI obtains not only the surface distribution of luminance and colorimetrics of micro-devices, also, much higher

spatial resolution of temperature than that by Infrared Imaging.


2018 年 10 月 23-25 日中国·深圳


139

SW208-201808131119

Operation behavior under extremely high injection level for GaN-based micron LED

Z.Z.Chen1, C.C.Li1, F.Jiao1,2, Q.Q.Jiao1, J.L.Zhan1, Y.B.Tao1, S.Y.Wang1, X.N.Kang1, G.Y.Zhang1,3, B.Shen1 1State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing

100871, China 2State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China

3Sino Nitride Semiconductor Co., Ltd, Dongguan 523500, Guangdong, China

Abstract

In this work, we have fabricated the different diameter micro pillar μLEDs with different wavelength and on different

substrates. The electroluminescence (EL) spectra and current-voltage (I-V) curves were measured. The high saturate current

density was achieved as 300 kA/cm2 for 20μm UV LED on GaN substrate. Efficiency droop was also improved greatly for

μLEDs. Crosslight software was used to simulate the transport and recombination processes under the high injection level.

Many-body effect was considered in the integrated quantum drift-diffusion model. The extreme high injection mechanism is

discussed.


2018 年 10 月 23-25 日中国·深圳


140

SW208-201808131947

A color gamut of 135% NTSC achieved by CsPbX3 perovskite quantum dots with enhanced stability

Shuyu Zhang, Qiongrong Ou, Yujun Xie

Fudan University

220 Handan Road, Shanghai, China

[email protected]

Abstract

All-inorganic CsPbX3 (X=I, Br, Cl) perovskite quantum dots (QDs) are very likely to become the next generation of QD

display due to their superior optical properties including extremely high photoluminescence quantum yield, narrow linewidth of

spectrum and broadly tunable emission. An emerging method which can avoid high temperature and inert atmosphere during the

fabrication process is room-temperature (RT) recrystallization, providing a promising route to low-cost mass-production of

CsPbX3 QDs. However, the stability performance of RT synthesized QDs under working conditions is not comparable to that of

conventional QDs, which severely limits their practical applications.

Here we demonstrate a facile and low-cost method to significantly improve the stability performance of RT synthesized

CsPbX3 QDs by effectively suppressing the unfavored grain growth and surface trap states. We systematically investigated the

thermal, photo- and water stability of our QDs and achieved stability performance superior to that reported in prior work. Based

on this, we fabricated QD-converted white LEDs using CsPbBr3 and CsPbBr1.2I1.8 QDs. These white LEDs are capable of

covering an extremely wide color gamut of 135% NTSC and 101% Rec. 2020. We believe this will pave the way towards

developing commercial perovskite QD display in the future.


2018 年 10 月 23-25 日中国·深圳


141

SW208-201808141514

Mini and Micro LED Chip Bonding Methods

Yongchang Sang, Soon Lee Tan

Elec-Tech Photoelectric Technology (Dalian) Co., Ltd

No.3 Xinxi Road, IT Industrial Park, Dalian Development Zone, Dalian, China

[email protected]

Abstract

Mini and Micro LED have attracted much interest due to its potential to be the next revolution in display technologies. We

define Mini LED as chip having smallest dimension ≥100um and Micro LED as chip having smallest dimension <100um.

Realizing Mini & Micro LED applications requires transferring and formation of electrical interconnections of the LEDs from

the Epitaxy substrate onto passive or active matrix substrate. Much have been discussed on the transfer but few on the formation

of high yielding and reliable electrical interconnections.

For Mini LED, due to its relatively large chip size, transfer of the Mini LED is viable by commercially available Pick and Place

technologies. Mini LED are typically Flip Chip LEDs with the cathode and anode on one surface of the chip. For a Mini Chip of

L*W 100um*200um the cathode and anode gap is <100um. Such small gap possess challenge to bonding yield. We discuss a

method to form high-yield and reliable SAC solder interconnect for Mini LED.

For Micro LED, due to its small chip size, there are presently no commercially available transfer technology. A wide variety of

Massively Parallel Pick and Place using electromagnetic, electrostatic, “sticky tapes” approaches to pick up Micro LED have

been suggested. Most address the transfer of micro LED but not the formation of electrical interconnect. We propose a simpler

and more feasible technology that first uses IR laser assisted bonding and UV laser lift-off to selectively bond and transfer micro

LED arrays from epi substrate to active matrix backplane directly without a need for an intermediate substrate.


2018 年 10 月 23-25 日中国·深圳


142

SW208-201808151715

Smart GaN-based micro-LED arrays

Xiaoyan Liu, Runze Lin, Zeyuan Qian, Honglan Chen, Xiaojie Zhou, Gufan Zhou, Xugao Cui, Xiaolin Zhou, Lirong Zheng,

Ran Liu and Pengfei Tian*

Fudan University

Room 313, Genetics Building, 220 Handan Rd., Shanghai 200433

[email protected]

Abstract

GaN-based micro-LED (μLEDs) arrays have demonstrated applications in micro-display as high brightness emitters,

solid-state lighting as the high-efficiency emitters and visible light communication (VLC) as the high-bandwidth data

transmitters. Through combining the applications above, a smart micro-LED system for big data and internet of things (IoT) can

be achieved. Up to now, it has not been reported that the GaN-based μLEDs can be also used as high-bandwidth photodetectors

(PDs) for VLC, which further expand the system functionality.

VLC is well known as a promising wireless communication technique for complementing off-the-shelf wireless

communication technology to meet the need of the increasing growth of high-speed communication. GaN LEDs-based VLC has

attracted significant interests. However, due to the low modulation bandwidth of the commercial broad-area LEDs limiting the

achievable data rate, novel GaN-based μLEDs were exploited to improve the modulation bandwidth and furthermore the data

rate. Most previous researches focused on using μLEDs as transmitters to deliver the signals. Nevertheless, the GaN-based

μLEDs can be also used as PDs for VLC.

In our work, a GaN μLED based photodetector receivers (referred as μLED-based PDs) were proposed and experimentally

demonstrated for high-speed parallel VLC, where the 405 nm violet laser diodes (LDs) with small beam divergence were

employed as transmitters. We studied the optoelectronic characteristics of the μLEDs-based PDs with different diameters of 100

μm, 60 μm and 40 μm and the parallel communication characteristics using the μLED-based PD array. The distance from the

transmitter to the receiver is around 1 m. For various μLED-based PDs, the maximum data rate of of 180 Mbps, 175 Mbps and

185 Mbps were obtained with corresponding bit-error rates (BERs) of 3.5 × 10-3, 3.7 × 10-3 and 3.5 × 10-3, respectively.


2018 年 10 月 23-25 日中国·深圳


143

SW208-201808152133

A GaN Micro-LED Based Underwater Wireless Optical Communication Subjected to Sea Salt,

Maalox and Chlorophyll

Honglan Chen1#, Peiyao Wang1#, Xiaoyan Liu1, Suyu Yi1, Xiaolin Zhou1, Erdan Gu1, Kai Huang2, Lirong Zheng1, Ran Liu1,

Xugao Cui1*, and Pengfei Tian1* 1Institute for Electric Light Sources, School of Information Science and Technology, Engineering Research Center of

Advanced Lighting Technology, and Academy of Engineering and Technology, Fudan University, Shanghai, 200433, China 2Department of Physics, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen

University, Xiamen, 361005, China #These authors contributed equally to this work.

*Emails: [email protected], [email protected]

Abstract

An underwater wireless optical communication (UWOC) system based on a 40 μm GaN micro-LED was proposed and

successfully demonstrated. The system’s performances under sea salt, Maalox and Chlorophyll added water were studied. The

measurements in bit error rates (BERs) and eye diagrams show that the performances of UWOC systems degrade significantly

with increasing concentrations of added substances in water. Maximum transmission data rates up to 933 Mbps, 790 Mbps, 800

Mbps and 910 Mbps were detected in the systems under conditions of tap water, 0.5% sea salt, 1 ml Maalox and 0.25 ml

chlorophyll in 414 L tap water, respectively.


2018 年 10 月 23-25 日中国·深圳


144

SW208-201809061654

High Volume Manufacturing MOCVD Solutions for Red, Green and Blue micro LEDs

Jens Voigt, Arthur Beckers, Adam R. Boyd, Thomas Korst, Martin Eickelkamp, Assadullah Alam, Michael Heuken

AIXTRON SE

Dornkaulstr. 2, 52134 Herzogenrath, Germany

[email protected]

Abstract

Micro-LED displays have the potential to excel over LCD and OLED displays in categories such as energy efficiency, pixel

density, refresh rate, brightness, transparency, contrast ratio and color gamut.

These outstanding features are attractive for a number of applications in display technology. For example, the high achievable

efficiency of LEDs can significantly improve the battery life of mobile devices such as smart watches. Improved brightness,

sharper contrast and an expanded colour gamut are desirable for automotive and TV displays.

Micro-LED processing uses very small red, green and blue LED chips as sub-pixels. The device structures are grown by

MOCVD with InGaN / GaN MQW on sapphire substrates for blue and green and AlGaInP / AlInGaP MQW on GaAs substrates

for red. Due to the immense number of subpixels required for these displays, it is essential that large quantities can be

transferred to a display in parallel mass processing without further binning control or sorting steps. This requires that the

Micro-LED wafers can be produced with extremely good color homogeneity and defect levels. MOCVD requirements for both

wavelength uniformity and defect density are substantially tightened over those for SSL, LCD backlight or mini LED

applications, whilst still high productivity and low cost levels have to be maintained.

AIXTRON’s Planetary Reactor® MOCVD technology is the established platform for production of compound semiconductor

devices with the highest standards regards uniformity, reproducibility and defect control; such as proven with VCSEL lasers for

3D sensor technology, which is one of the key drivers for current high volume demands. The same combination of requirements

does apply for Micro-LED technology: A high throughput of structures incorporating epitaxial layers with very demanding

precision at lowest defect levels.

The Planetary Reactor® technology has been proven to enable the necessary production conditions for Micro-LEDs, for all

three colors. In this paper the respective main aspects are discussed.


2018 年 10 月 23-25 日中国·深圳


145

SW208-201809251647

Shaping of the μ-LED chips aimed at formation of internal micro-reflectors, as a way of

considerable Light Extraction Efficiency improvement

Mark Ramm

STR Group – Soft-Impact, Ltd., 64 Bolshoi Sampsonievskii pr., Bld. E., 194044 St. Petersburg, Russia

Correspondence: [email protected]; Tel.: +7-812-643-4186

Abstract

Micro-LEDs are light sources operating at very high current densities, where the device self-heating, efficiency droop caused by

Auger recombination, and surface recombination become the major factors limiting the device performance. In particular,

surface recombination results in a shift of the peak μ-LED efficiency towards higher current density and in a decrease of its

value when the device dimensions are reduced. Earlier studies of μ-LEDs were focused primarily on their current-modulation

characteristics. Only recently, the efficiency improvement had become a hot topic in the research and development of μ-LEDs.

Typically, maximum values of external quantum efficiency (EQE) of μ-LEDs did not exceed 10%, which could be attributed to

non-optimal light extraction from the LED dice. A record EQE of 40.2% at the current density of 35 A/cm2 was recently

demonstrated for 10×10 μm2 devices and light extraction to a silicone with the refractive index of 1.41 [1]. Those μ-LEDs

utilized profiled sapphire as the substrate for LED structures and minimized the area of metallic electrodes on the emitting

surface of the devices in order to improve their LEE.

An alternative approach, suggested as a design unit of large-size AlGaInP red LEDs [2] rather than for single μ-LEDs, was

based on flip-chip device mounting on a heat sink. Here, inclined walls of the mesa formed by etching after growing the LED

structure served as micro-reflectors for emitted photons. After flip-chip mounting of the wafer on a carrier-substrate, the original

substrate was removed and the back surface of the n-contact layer was textured to increase LEE [2]. The use of such

micro-reflector seems to be quite promising for InGaN-based μ-LEDs, provided that geometry of the LED die is carefully

optimized with account of particular properties of nitride semiconductors and other materials employed.

To optimize a μ-LED design, modeling and simulation of its operation is a powerful approach. Since μ-LEDs operate at

extremely high current densities, electrical, thermal, and optical phenomena become strongly coupled with each other, generally

requiring joint 3D simulations. In this paper, using the SimuLED software package [3] we analyze operation of the μ-LED

equipped by micro-reflectors and suggest an effective way of the efficiency improvement, based on shaping the μ-LED dice.

The main characteristics of μ-LEDs with optimized design are calculated and compared with those of large-size devices.

[1] D. Hwang et al., Sustained high external quantum efficiency in ultrasmall blue III–nitride micro-LEDs, Appl. Phys. Express

2017, 10, 032101.

[2] R. Windisch et al., InGaAlP Thinfilm with high luminous efficiency, Proc. SPIE 2004, 5366, 43-52.

[3] SimuLED – engineering tool for LED and laser diode design and optimization. Available online:

http://www.str-soft.com/products/SimuLED/index.htm.


2018 年 10 月 23-25 日中国·深圳


146

SW208-201810031622

三基色 LD 激光显示技术

Laser display technology based on RGB semiconductor lasers

毕勇中国科学院理化技术研究所

摘要：

红绿蓝三基色半导体激光器（LD）具有电激发、高效率、长寿命、小型化、低成本的优点，是激光显示走向产业

化的最佳光源。近年来，在国家重大科技计划和产业政策的支持和引导下，三基色 LD 激光显示技术和产业取得了重大

进展，在实用化三基色 LD 激光模组制备与批量生产、多手段协同散斑抑制、复杂/精密整机一体化设计与制造等产业

化关键技术方面取得了突破，开发出系列化三基色 LD 激光显示样机/产品，并在家居、公共大屏幕、影院以及工程领

域实现了商业应用

147

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