Presented byRAHUL RAJENDRA BIBAVESEAT NO.- T120102509Guided byPROF. G.R.ROKDE.

LIGHT EMITTTING POLYMERS

WELCOME

INTRODUCTION TO LEP It is a polymer that emits light when voltage is

applied to it. The structure comprises of thin film semi

conducting polymer sandwiched between anode and cathode

1950 : Bernanose applied high voltage alternating current to thin film

1977 : conducting polymers are discovered

1990 : Fried invented new Light Emitting Polymers called as PPV

Birth of “LIGHT EMITTING POLYMERS”!!!!!!!!

HISTORY

Structure Thin film of semiconducting

polymer sandwiched between an ANODE and CATHODE.

ANODE: ITO(Indium Tin Oxide)

CATHODE: Metals (depends upon the type of LEP)

SUBSTRATE: Glass, clear plastic (depends upon the type of LEP)

Voltage is applied between anode and cathode

Metal Cathode Polymer

Glass Substrate

Transparent Anode (ITO)

WORKING Due to applied voltage

electrons and holes will migrate to polymer lattice.

They will combine together to form excitons

Excitons returns to initial state by emitting radiation.

Types of LEPs

FLEXIBLE STACKED TRANSPARENTORGANIC LEPs ORGANIC LEPs ORGANIC LEPs

Manufacturing methods

1.Spin coating process

2. Printer based Technique

1. Spin coating process: In this a glass substrate is spinned at a

fixed angular velocity on which a plastic solution is poured.

2. Printer based Technique: LEPs can be patterned using a wide

variety of printing techniques. The most advanced is ink jet printing with a resolution as high as 360 DPI.

Operates with 3.3volts only As active material is plastic cost is much

less than CRT, LCD. Greater power efficiency than all other

flat panel displays Life time of more than 30,000 hours Can be viewed at any angle Fast switching speed i.e. 1000 times

faster than LCDs. Higher luminescence efficiency

ADVANTAGES

Limitations Voltage drops may affect the performance.

Limited market availability.

Aging of LEP Degradation of luminescence Light intensity gradually decreases. Disintegrate due to contact with oxygen.

Multi or full color cell phone display HD Television display Light weight wrist watches Military applications Aircraft cockpit instrumentation

Applications

CONCLUSION Have both electrical and optical property

A low cost solution for flat panel display.

Many manufactures are working to introduce a revolutionary changes in the market.

Hazardless to environment.

Simpler and cheaper

Have some limitations

Till it is the superior technology………for the future…..

1. NEWS & INFORMATIONImagine a day when you are reading a newspaper that is capable of showing pictures and video, is continuously updating itself with the latest news via WI-FI connection, and is also so thin and flexible that you can roll it up put it in your backpack or briefcase.

FUTURE SCOPE

2.ADVANCEMENTS IN THE HOMEONE OF THE MANY POSSIBILITIES IS TO REPLACE REGULAR WALLS OR WINDOWS WITH SIMILAR SIZED OLED INSTALLATIONS WHICH WILL “ LEAD TO USER-DEFINABLE WINDOW SPACES”.THESE WALLS WILL USE TRANSPARENT OLEDS THAT WILL MAKE IT POSSIBLE TO HAVE CERTAIN AREAS OPAQUE WHILE OTHER AREAS CLEAR , DEPENDING ON WHAT THE HOMEOWNER WOULD LIKE.