Brilliant Plastics

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Overview

Introduction

What is polymer light emitting diode (PLED)?

Basic Principle of PLED

Efficiency of Polymer LED devices

Polymer LED display Technology

Advantages and Disadvantages of PLED DisplayTechnology

Future Outlook

Conclusion



Polymer Light Emitting Diode DisplayTechnology



What is a Polymer light emitting diode(PLED)?



Basic Principle and Technology of

PLED Electrons are injected into the conduction band

and holes are injected into the valence band of the

polymeric semiconductor The injected electrons and holes can diffuse

towards each other and finally recombine. By this

process, neutral excitations are created

When these exited states decay into their ground

state, a characteristic fluorescence is generated.



Structure of a Polymer LED



How does a Polymer LightEmitting Diode Work?

http://animation.ppt/






Efficiency of Polymer LED devices

Efficiency of Organic El Devices is given by:

ηext= ηintηp= γηrφf ηp

ηext = external quantum efficiency

ηint = Internal quantum efficiency

ηp = Light out-coupling effect

γ = charge carrier balance factor (e/h)

ηr = efficiency of exciton productionφf = Internal quantum efficiency

luminescence

Maximum external quantum efficiency is ~ 5%



Polymer Light Emitting Diode Display

Technology Polymer Light Emitting Diode technology enables

full color, full-motion flat panel displays with alevel of brightness and sharpness not possible withother technologies.

PLEDs are self-luminous and do not requirebacklighting, diffusers, polarizers, or any of theother baggage that goes with liquid crystaldisplays.

There are two forms of PLED Displays:

Passive-matrix and Active-matrix.



Passive-Matrix PLED display

The passive-matrix PLED display has a simple

structure and is well suited for low-cost and low-information content applications such as

alphanumeric displays. It is formed by providing

an array of PLED pixels connected by intersecting

anode and cathode conductors.



Active Matrix PLED Display In an active-matrix PLED display, each

individual pixel can be addressed

independently via the associated TFT’s andcapacitors in the electronic back plane.

In these active matrix displays, each pixel

always radiates precisely the amount of light into the environment that is needed for

the desired color impression.



The advantages of PLED displays relative to

liquid crystal display (LCD) monitors: Brilliant, highly luminous colors, an unimpeded

viewing angle of nearly 180 °, and an extremely

thin structure. Simpler structure

self-luminescent

High Resolution

Power Usage – Takes less power to run (2 to 10

volts).

Flexibility



Disadvantages of PLED Displays: Engineering Hurdles

Color

Overcoming LCD’s

high sensitivity to contaminants



Future Outlook

The PLED technology faces a bright future in

the display market

PLEDs might replace some fluorescent lights

in the next 10 --20 years.

PLED sheets could replace wallpapers or coat

ceilings and provide very pleasant uniformlighting in any home or work area



Conclusions

These brilliant Plastics will soon enable us notonly to make innovative light sources, but also

their optoelectronic counterpart — the solar cell Polymer LEDs are much more promising than

previously thought

Organic semiconductors will not replaceestablished silicon technology; but they willoffer inexpensive solutions for simpleapplications



For all we know and can hope for.... PLEDs

could change the ways in which we seethings….

Brilliant Plastics

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