1. LIGHT EMITTTING
POLYMER

2. 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

3.  Energy difference between the valence band and
conduction band of the semiconducting polymer
determines the wavelength, i.e., color of emitted
light

4. STRUCTURE AND WORKING
 It’s display solely consists of the polymer
material manufactured on a substrate of glass or
plastic and doesn’t require additional polarizers
that are typical of LCDs

5. TYPES OF LEPS
1.Flexible
2.Stacked organic(SOLEP)
3.Transparent organic(TOLEP)

6. Stacked Transparent
FLEXIBLE LEP
LEP LEP

7. MANUFACTURING METHODS
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.

8. ADVANTAGES
 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

9. LIMITATIONS
 Ageing of LEP
 Space charge effect

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

11. CONCLUSION
 LEP technology is now set to change the products
we use to view the world

12. Ch.Ravi (08911A0474)
B.V Chalapathi (08911A04B1)