PRAYAG RANJAN SETHI EC200 12717 2 Presented by Under the guidance of LIGHT EMITTING POLYMERS
Light Emitting Polymers
Dec 01, 2014
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PRAYAG RANJAN SETHIEC200127172
Presented by
Under the guidance of
LIGHT EMITTING POLYMERS
INTRODUCTIONLEP is an emissive technology that emits light as a function of electrical operation.It exhibits electroluminescent characteristics.It emits light under the application of electric field.e.g- polyvinyl chloride.LEP was discovered in 1990
PRAYAG RANJAN SETHI EC200127172
CONDUCTING POLYMERS Three type of conducting polymer are there1.conductor(bg-1ev)2.semiconductor(bg-2.2ev)3.insulator(bg-10ev)
PRAYAG RANJAN SETHI EC200127172
Structure of LEPLEP consists thin film of polymer sandwiched between an anode and a cathode.Indium tin oxide(ITO) is usually as anode.Metals are used as cathode.
PRAYAG RANJAN SETHI EC200127172
How LEP works
Electric field is applied between two electrodes.The electron are injected from cathode and holes from anode.The injected charges recombined &decay radiatively.
PRAYAG RANJAN SETHI EC200127172
Electric field is applied between two electrodes
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Then both types of charge carriers migrate into the polymer
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Positive and negative charge carriers combine and generate an neutral exited state( )
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FabricationFirst the polymer coated on the ITO surface.Then four steps are done.•cleaning.•spin coating•depositing•testing
PRAYAG RANJAN SETHI EC200127172
Cleaning
Each surface is cleaned by alcohol based cleaner.Then it is put to a UV ozone cleaner where it is bombarded by UV rays.
PRAYAG RANJAN SETHI EC200127172
SPINCOATING
ITO is placed on the spinning apparatus.Next several polymeric drop smeared on the surface.Once coating completed it is taken to the surface scanner for close scanning.The ITOs are placed on the spinner and than the polymer is speed over the surface.
PRAYAG RANJAN SETHI EC200127172
DEPOSITINGThe samples are placed above the electrodes.The electrodes are connected via high resistance metal alloy.Once voltage is increased the airborne molecules scatters and deposited on the glass.The thickness deposited depends upon the properties of polymer & glass.
PRAYAG RANJAN SETHI EC200127172
TESTING
PRAYAG RANJAN SETHI
EC200127172
Once deposition is completed,the samples are tested for light emittance.
This simply done by creating electric potential between the electrodes of the substrate.
ADVANTAGES
PRAYAG RANJAN SETHI
EC200127172
Low energy consumption
Usefull for large area lighting
Simple to use technology
Permits flexible lighting and displays
A technology for the future
It has both electrical and optical property.It is simpler &cheaper. It permits flexible lighting and display .It is technology fi\or the future.
PRAYAG RANJAN SETHI EC200127172
Conclusion
THANK U !!
PRAYAG RANJAN SETHI EC200127172
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