1

Advantage of the LED

(OSRAM)

2

LED Cross-Section View

Substrat (absorbierend

oder transparent)

~ 0.25 mm

內部量子效率

+

−

引出效率

p- Window Layer

p- Cladding Layer

n- Cladding Layer

n- Substrate

i- Active Layer

3

電流驅動發光原理

4

Different Kinds of Electric Transition

E2

E1

E2

E1

hν 12

E2

E1

hν 12

E2

E1 hν 12

hν 12

(Before) (After)

(a) Absorption

(b) Spontaneous Emission

(c) Stimulated Emission

(Photodetector)

(LED)

(Laser Diode)

E2

E1

hν 12

E2

E1

Eg (Bandgap)

5

LED發光光譜及其採用材料

Blue B = Blue (InGaN) 470nm

B = Blue (GaN) 466nm

Green

V = Verde-Green (InGaN) 505nm

T = True Green (InGaN) 525nm

P = Pure Green (GaP) 560nm

G = Green (GaP:N) 570nm

White

W = White (GaN) (x=0.32/y=0.31)

W = White (InGaN) (x=0.32/y=0.31)

Yellow Y = Yellow (AlGaInP) 587nm

Orange O = Orange (AlGaInP) 605nm

Amber A = Amber (AlGaInP) 615nm

Red S = Super-Red (AlGaInP) 630nm

H = Hyper-Red (AlGaAs) 645nm

s

0

0.1

0.2

0.3

0.4

0.,5

0.6

0.7

0.8

0.9

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

blue

green

red

yellow

white

Colour triangle

(OSRAM)

6

AlGaInP及InGaN LED

540 560 580 600 620 640 660

Emission Wavelength [nm]

20

50

1000

200

AlGaInP

Traditional

20 mA

Lum

inou

s Flu

x @

20m

A

Orange Yellow Superred Hyperred

AlGaAs

GaP GaAsP

Lum

inou

s Flu

x @

20m

A

20

50

100

520 500 480 460

Green Verde Blue

InGaN

on SiC on Sapphire

on GaAs

1000

200

500

100

500

(OSRAM)

7

單晶磊晶層的成長(AlGaInP)

(E. F. Schubert, “Light-Emitting Diode”)

8

單晶磊晶層的成長(AlGaInN)

Lattice Constant a0 (Å)

Ban

dgap

Ene

rgy

Eg (

eV)

9

有機金屬氣相磊晶(MOVPE)設備

(AXITRON)

10

The Planetary Reactor

wafer handler

4” wafer on rotating satellite

main susceptor disk

collector ring (molybdenum)

(AXITRON)

11

質流控制器(MFC)

(M. Quirk and J. Serda, “Semiconductor Manufacturing Technology”)

12

LED Chips or Dies

13

LED Measurement (Probe Station)

14

LED發光特性的改善

磊晶製程

LED-Epitaxy

晶粒製程

LED-Process

封裝製程

LED-Package

15

Current Spreading Layer

(a) 2 µm (b) 15 µm (c) 50 µm

125

Top Contact

P-GaP Current Spreading Window 1.0

0.5

(a)

(b)

(c)

0 0 25 50 75 100

Distance from Center of Chip, x(µm)

Nor

mal

ized

Cur

rent

Den

sity

, J(x

) p-Contact

n-Contact

2-50 µm p-GaP Window Layer

1.0 µm AlInP Si-doped

n-GaAs Substrate

0.5-1 µm AlInP Mg-doped 0.5-1 µm AlGaInP Undoped

16

Current Spreading Layer

Without a spreading layer

With a spreading layer

(E. F. Schubert, “Light-Emitting Diode”)

17

Wafer Bonding

p-Contact

n-Contact

p-GaP Window (~50µm)

Wafer Bonded n-GaP (~200 µm)

AlGaInP (~2 µm)

GaP Epilayer LED Structure

GaAs Substrate

GaP Epilayer LED Structure

GaP Epilayer LED Structure

GaP Substrate GaAs Substrate

GaP Epilayer LED Structure

GaP Substrate

(Temperature and Force)

(LumiLEDs)

18

Extraction Efficiency

(E. F. Schubert, “Light-Emitting Diode”)

19

Surface Roughening

Before etching

After etching

(Fujii et al., APL, v84, p855, 2004)

20

AlInGaP Chip Efficiency Improvement

~ 30x (LumiLEDs) ~ 18x ~ 3x

Batwing

21

Effect of Epoxy

( )airη ( )epoxyη

(E. F. Schubert, “Light-Emitting Diode”)

22

Different Kinds of LED Packages

(http://en.wikipedia.org/wiki/LED)

(LED Lamps) (LED Displays)

(SMT LEDs) (PCB LEDs) (SunLED)

23

銲線(Ball Bond)

銲線完成照片 (CREE)

24

Flip-Chip InGaN LED

(LumiLEDs)

(Nichia)

N-GaN

Sapphire

Buffer layer

P-GaN MQW

P-Contact

N-Contact

Transparent contact layer

N-GaN

Sapphire

Buffer layer

P-GaN MQW

P-Metal

N-Metal

Submount

Solder

Conventional InGaN LED

Flip-Chip InGaN LED

25

Packaging Technology (Power Improvement)

(Low Power LED) (High Power LED)

(LumiLEDs)

26

RGB LEDs (2)

Diffusion cap

27

Blue LED + Yellow Phosphor (1)

演色性評價指數: ~ 80 色溫: 5000 K.. 6500 K

藍光Blue LED + 螢光粉phosphor = 白光white LED

(OSRAM)

28

Blue LED + Yellow Phosphor (2)

29

Street and Roadway

(LumiLEDs)

30

Product Design (LED Curing System)

(Innovation in Optics)

Heat Sink

31

Traffic Signals

150W 15W (LumiLeds high power LED *12)

Sun Phantom

Prevention

32

Media Boards

Times Square, New York

~ 1000 m2 LEDs = 19 mil. LEDs

(Thomas Swan)

33

Road Lighting

Very bright and can be seen from up to 4 miles away

(Sweden)

34

Elevated Taxiway LED

(Dialight)

35

LED Automotive Lighting

Mercedes Benz 128 LEDs in two different colors

18 in each mirror (Amber) 32 in every stop light

28 high mount stop light

Lexus Interior Lighting Ford Tonka F-350 500 lm*2 for low-beam operation with side parking lights

36

Forward Lighting

(LumiLEDs)

37

Flashlights and Lighting for Diving

(Fa&Mi)

38

Backlighting Source

For all types of displays: LCD Televisions, LCD monitors on laptop computers, and various custom sized LCD displays.

(LumiLEDs)

39

Wide Area Lighting

(LumiLEDs)

40

Residential Lighting Application

(LumiLEDs)

41

Capsule Endoscopy