POLYMER LED
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POLYMER LED
Presented By
UMAKANTA MOHAPATRO ROLL # EI200113370
December 2004
Under the Guidance of
Mr. Prabhat Kumar Mohapatra
POLYMER LED
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INTRODUCTION Polymer LED (light-emitting diode)- sometimes
called light-emitting polymer or polyLED - is a
technology based on the use of polymer as the
semiconductor material in LEDs. It is a novel technology to manufacture very thin light sources and displays Polymers are large molecules widely known as
plastics.
POLYMER LED
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Light Emitting Polymers convert electrical power into visible
light:
Light EmittingPolymer
electrical power
FluorescentPolymerUV-radiation
This is related to the fluorescence of polymers where UV-radiation is converted into visible light:
visible light
visible light
Text
mar
ker
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A polymer needs to show fluorescence and to conduct electricity.
UV radiationvisible light
+
electrical charge
to be a Light Emitting Polymer.
POLYMER LED
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A thin film of light Emitting Polymer put between two electrodes will glow...
Light Emitting Polymer Device
Substrate
Metallic Counter Electrode
Thin Plastic Film of LEP
Transparent Electrode
Emitted light
+-
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•On each cm² of a device running at standard brightness
this happens1.000.000.000.000.000
times per second!!!
•Positive and negative charge carriers combine and generate an neutral exited
state. This exited state decays and generates Visible light
•If voltage is applied, positive charge carriers
move into the anode,negative charge
carriers into the cathode!
POLYMER LED
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Like an ink a solution of Light Emitting Polymer can be used to easily "paint" an electrical light source onto an appropriate substrate. it's like 'painting' an electrical light!
+
-
POLYMER LED
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By engineering the chemical structure of the
Light Emitting Polymer all emission colours can be obtained.
POLYMER LED
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•Because plastic materials are flexible and robust even non-planar displays can be manufactured. LEP- Non Planar Displays
Light Emitting Polymer Film Transparent Protective Film
Protective Film
Covion- flexible displays
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Polymer electronics laboratory
The photo shows where each of the following steps in the
fabrication sequence takes place. 1) Clean substrates in ultrasonic bath (not shown).
2) Clean substrates in dust free work area.
3) Transfer substrates into glove box.
4) Spin coat polymer film.
5) Transfer parts into glove box.
6) Coat top metal electrodes in vacuum evaporator.
7) Test polymer LEDs.
POLYMER LED
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Light Emitting Polymers cover a large range of applications:
Easy to use technology.Thin and light weight displays for portable electronics. Very high brightness. Low operating voltage (2 - 6 Volts).All colours possible.All shapes and non-planar displays possible.
POLYMER LED
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0
2
4
6
8
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0 1 2 3 4 5 6Voltage [V]
Pe
rfo
rma
nc
e [
Cd
/A o
r lm
/W]
0.01
0.1
1
10
100
1000
10000
Lu
min
an
ce
de
ns
ity
[C
d/m
²]
Luminance Efficiency [Cd/A]
Power Efficiency [lm/W]
Luminance density [Cd/m²]
16 lm/W
13.5 Cd/A
"... high brightness at low operating voltage"
POLYMER LED
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Light Emitting Polymers have a lot of advantages … Low energy consumption Useful for large area lighting Simple to use technology Permits flexible lighting and displays A technology for the future
disadvantages: Non-uniform color displays
Manufacturing process is costly
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PLED Vs. LED LED is made from inorganic emitting material like
silicon, III-IV semiconductors, but PLED is made
from inorganic material like polymers.
LED is used as narrow field of application, but
PLED is used as very wide application field.
PLED gives more benefits than LED.
PLED Vs. LCD Full-color OLED-based displays will have replaced
active matrix LCDs as the market dominant display
technology by around 2010.
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LEP technology combines simple solid-state construction, low drive voltage and high efficiency OLEDs with large area pattern ability and the possibility of flexible substrates.
LEP technology will initially be used to extend the performance of current displays in mobile communication, computers and consumer electronics.
The fast switching speed of LEP would allow small, high-resolution screens to be constructed
CONCLUSION
POLYMER LED
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THANK YOU !!!
POLYMER LED
UMAKANTA MOHAPATRO EI200113370
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