PRESENTED BY MANVITH

Organic light-emitting diodes(OLED)

OUTLINE INTRODUCTION HISTORY WORKING PRINCIPLE TYPES OF OLED APPLICATIONS ADVANTAGES DISADVANTAGES REFERENCE

INTRODUCTION OLED-Organic Light Emitting Diode Organic-Organic materials Definition- Emissive electroluminescent layer is a film

of organic compounds which emits light in response to an electric current

Electroluminescent layer – organic semiconductor material is sandwiched between two electrodes

One of these electrodes is transparent

ORGANIC COMPOUNDS

Aluminum 8-hydroxyquinolinate - Alq3

Polyaniline

Polyfluorene

HISTORY

First developed in the early 1950’s in France by applying a high-voltage alternating current field to crystalline thin films of acridine orange and quinacrine

1960’s – AC – driven electroluminescent cells using doped anthracene was developed

The first diode device was invented at Eastman Kodak in the 1980’s by Dr. Ching Tang and Steven Van Slyke

1990 – electroluminescence in polymers was discovered

2000 - Alan J.Heeger & Hideki Shrikawa received Nobel Prize in chemistry for “The discovery and development of conductive organic polymer

2008 – announced the creation of consortium including Sony, Toshiba to produce OLED screen

Cathode Emissive Layer Conductive Layer Anode Substrate

How OLED works?

Architecture of OLEDs

o Conducting layer - This layer is made of organic plastic molecules that transport "holes" from the anode.

o Eg: polyaniline. Polystyrene.

o Emissive layer - This layer is made of organic molecules that transport electrons from the cathode; this is where light is made.

o Eg: polyfluorene, Alq3 

Organic layers:

Cathode (may or may not be transparent depending on the type of OLED) - The cathode injects electrons when a current flows through the device

Eg: Mg, Al, Ba, and Ca • • Substrate - The substrate supports the OLED Eg: clear plastic, glass, foil Anode (transparent) - The anode removes electrons (adds electron holes) when a current flows through the device Eg: Indium Tin Oxide

1. Voltage applied across Cathode and Anode

1. 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

TYPES OF OLEDs

1. Passive-matrix OLED2. Active-matrix OLED3. Transparent OLED4. Top-emitting OLED5. Flexible/Foldable OLED6. White OLED7. Phosphorescent OLED

1. Passive-Matrix OLED (PMOLED)

Perpendicular cathode/anode strip orientation

Light emitted at intersection (pixels)

Large power consumption

Used on 1-3 inch screens

2. Active-Matrix OLED (AMOLED)

Full layers of cathode, anode, organic molecules

Thin Film Transistor matrix (TFT) on top of anode

Less power consumed then PMOLED

Used for larger displays

DIFFERENCE

Passive OLEDs• The organic layer is between

strips of cathode and anode that run perpendicular

• The intersections form the pixels•  Easy to make• Use more power• Best for small screens

Active OLEDs• Full layers of cathode and

anode• Requires less power• Higher refresh rates• Suitable for large screens

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 Transparent Cathode Used with Active Matrix

Device Smart card displays

5. Foldable OLED

Flexiable metallic foil or plastic substrate

Light weight and ultra thin

Reduce display breaking

6. White OLED Emits bright white light Replace fluorescent lights Reduce energy cost for

lighting True Color Qualities Environmental friendly

7. Phosphorescent OLED

Use the principle of electroluminescence to convert 100% of electrical energy into light

Good energy efficiencies Reduce heat generation Operate at very low voltage Long operating life time Environmental friendly

APPLICATIONS

Display sources

Mobile phones

Keyboards

Digital watches

Light sources

Optimus Maximus Keyboard

• Each key can be programmed

to perform a series of functions

• Keys can be linked to

applications

• Display notes, numerals,

special symbols, etc...

OLED Televisions

• Released XEL-1 in February 2009. 

• First OLED TV sold in stores.

• 11'' screen, 3mm thin

• Rs.2,50,000

• Weighs approximately 1.9 kg

• Wide 178 degree viewing angle

• 1,000,000:1 Contrast ratio

Sony

ADVANTAGES OF OLEDs

Much faster response time Consume significantly less energy Wider viewing angles Thinner display Better contrast ratio Safer for the environment Has potential to be mass produced inexpensively OLEDs refresh almost 1,000 times faster then LCDs

OLED Displays Vs. LCD and Plasma

Cheaper way to create flexible lighting Requires less power Better quality of light New design concepts for interior lighting

OLED Lighting Vs. Incandescent and Fluorescent

ADVANTAGES

Brightness Contrast Viewing angles Power consumption Light weight Better power efficiency Response time

DISADVANTAGES OF OLEDs

OLED Displays Vs. LCD and Plasma

• Cost to manufacture is high

• Constraints with lifespan

• Easily damaged by water

• Limited market availability

OLED Lighting Vs. Incandescent and Fluorescent

• Not as easy as changing a light bulb

 

    

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

Future Uses for OLEDLighting• Flexible / bendable lighting• Wallpaper lighting defining new ways to light a space• Transparent lighting doubles as a window

 Cell Phones• Nokia 888

    

Reference Advanced microsystem for automotive applications by Sven Kruger,

Wolfgang Gessner, Springer- Verlag Heidelberg, New York 2001 page no62.

Organic molecule solids by M. Schwoerer, Hans Christoph, Wolf, Wiley vch verlag publishers ,New York,2007,page 389

Physics of organic semiconductors by Wolf Gang Brutling ,VBH publishers, New York,1999, page no 451

Highly efficient OLED,S with phosphorescent Materials by Hartmut Versin, Wiley Publishers New York 2000, page no 121

Organic electronic materials by Riccardo Farchichi,G.Grosso,2000, page no 135

Active matric OLED displayers by Michael Kroger,Cuviller Verlay publishers ,2007, page no 4

Organic light emitting divices by Joseph Shinar-Springer- Verlag, New York, 2004, page no 150

Organic light emitting material and devices by Zhigang Li, Hong Meng CRC publishers, New York, 2005, page no 34

Semiconductor devices by Kanaan Kano,Prentice Hall of india PVT,New delhi,2005,Page no 429

Printing unit and Organic light emitting diodes by Jan Kalinowski,

Conjugated Polymers and Related Materials by A. J. Heeger, in W. R. Salaneck, I. Lundstrom, B. Ranby, oxford university press, 1993.page no.234

manufacturing line for manufacturing flexible organic El display by kenichi kuba etal, Pub no. US2005/0016405

http://www.cepro.com/article/study_future_ bright_for_oled_lighting_market/

http://www.oledresearch.com/oleds/oledshistory.html

www.oled-info.com

http://optics.org/cws/article/industry/37032

http://jalopnik.com/5154953/samsung-transparent-

oled-display-pitched-as-automotive-hud