ORGANIC LIGHT EMITTING DIODE

AN OLED is a Organic Light Emitting DiodeIn which emissive electroluminescent layer is a film of organic compound which emits lightIn response to an electric current. This layerOf organic semiconductor suited between to Electrodes. Generally one of the electrode is Transparent. OLEDS are used to create digital displays in devices such as screens. An OLED works without back Light. Inflow ambient light conditions such as a dark room an OLED screens can achieve a higher contrast ratio than an LCD ,whether the LCD uses cold Cathode Fluorescent Lamps or LED back light. OLED technology was firstly developed in1987 at East men kodak company by Tang and Van slyke using small molecule (sm-OLED). IN 1990 Richard friend and Jeremy Burroughes and DonaldBradley discovered electroluminescence capabilities from conjugate polymers so lying down the new generation of flat panel displays

(OLED)

How OLED EMITS LIGHT1. Voltage applied across

Cathode and Anode1. Typically 2V-10V

2. Current flows from cathode to anode

1. Electrons flow to emissive layer

2. Electrons removed from conductive layer leaving holes

3. Holes jump into emissive layer

3. Electron and hole combine and light emitted

OLED ProcessProcess involves to stages:-

1. Pre encapsulation process2. Continuous operation inside chambers

1. Passive-Matrix OLED (PMOLED) Perpendicular cathode/anode

strip orientation Light emitted at intersection

(pixels) External circuitry

Turns on/off pixels External circuitry Large power consumption

Used on 1-3 inch screens Alphanumeric displays

2. Active-Matrix OLED (AMOLED) Full layers of cathode, anode,

organic molecules Thin Film Transistor matrix (TFT)

on top of anode Internal circuitry to determine

which pixels to turn on/off Less power consumed then

PMOLED Used for larger displays

3. Transparent OLED (TOLED)

Transparent substrate, cathode and anode

Bi-direction light emission

Passive or Active Matrix OLED

Useful for heads-up display Transparent projector

screen glasses

4. Top-emitting OLED (TEOLED)

Non-transparent or reflective substrate

Transparent Cathode

Smart card displays

Used with Active Matrix Device

OLED Advantages over LED and LCD Thinner, lighter and more flexible

Plastic substrates rather then glass High resolution (<5um pixel size) and fast switching (1-

10um) Do not require backlight, light generated Low voltage, low power and emissive source Robust Design (Plastic Substrate) Larger sized displays Brighter- good daylight visibility Larger viewing angles -170o Colour Gamut comparable to CRT, with potential to get better – Striking

visual appeal Thinner – No backlight Less Expensive than LCD due to lesser components

White + Color Filter route takes away some of this advantage Potential for printing in manufacturing. Flexible and Conformal Displays

OLED Disadvantages

Lifetime White, Red, Green 46,000-230,000 hours

About 5-25 years Blue 14,000 hours

About 1.6 years Expensive Susceptible to water Overcome multi-billion dollar LCD

market

OLED Roadblocks

Materials Small molecule lifetimes still not OK for TV

applications, although robust for mobile phones Polymers struggling with material stability

Manufacturing UHV process not easily scalable to larger Mother

Glass. Currently, manufacturing restricted to 370 x 470mm

Printing (Polymers) still in R&D stage Active Matrix Back plane

Incompatible with the existing a:Si technology LTPS technology (considered suitable for current

driven devices) suffers from uniformity problems and restricted to displays < 8”

5.Applications: Foldable OLED

Flexable metalic foil or plastic substrate

Lightweight and durable

Reduce display breaking

Clothing OLED

MARKET FORECAST:- O LED lighting will pick up in 2011 and reach $6.3B by 2018 The O LED lighting market will reach $1.5B by 2015 Large investment made on OLED lighting in EU, US, Japan and Korea. Europe is currently the leading in OLED lighting in terms of projects , GOVT

funding and participating companies Over 100 companies and universities are currently working on OLED lighting.

OLED lighting market forecast

Limited use caused by degradation of materials.

OLED will replace current LED and LCD technologies

Expensive Flexibility and thinness will enable

many applications

Conclusions

Q&A