Study on Air-Water & Water-Water Heat Exchange in a Finned Tube Exchanger
OLED basics
1. Organic Light Emitting Diode
(OLED)
Presented by:
Muhammad Umar 2012-MS-EE-50
Waqar Mahboob 2012-MS-EE-96
Ahmed Bilal Hussain 2012-ME-EE-14
Iayan Khalid 2012-MS-EE-20
2. Contents
Introduction
History
Structure of OLED
How OLED works?
Types of OLEDs
Advantages and disadvantages
Comparison
Conclusion
References
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3. Introduction
Emerging Technology for displays in devices.
Main principle behind OLED technology is
electroluminescence. [1]
Offers brighter, thinner, high contrast, flexible displays.
OLEDs are solid state devices composed of thin films of
organic molecules that is 100 to 500 nanometres thick.
They emits light with the application of electricity.
They doesn’t require any backlight. i.e., they are self
emitting.
They are made from carbon and hydrogen.
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5. History
The first OLED device was developed by Eastman Kodak in
1987.
In 1996, pioneer produces the world’s first commercial
PMOLED.
In 2000, many companies like Motorola, LG etc developed
various displays.
In 2001, Sony developed world’s largest fullcolor OLED.
In 2002, approximately 3.5 million passive matrix OLED sub-
displays were sold, and over 10 million were sold in 2003.
In 2010 and 2011, many companies announced AMOLED
displays.
Many developments had take place in the year 2012 for5
7. Structure of OLED
Substrate( made up of Plastic or Glass)
Anode. (made up of ITO)
Organic Layer.
Cathode. (made up of oxides of Calcium,
Aluminium or Magnesium)
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8. Single Layer and Multilayer
OLEDs
Single Layer:
◦ Contains only one organic layer between two
electrodes.
◦ Having Low Operation Efficiency.
Multi-Layer:
◦ Two or more layers are between electrodes
depending on the application.
◦ Two most frequently used layers are HTL and ETL.
◦ Conductive layer (Hole Transport Layer).
made up of polyaniline or metal-phthalocyanine.
◦ Emissive layer( Electron Transport Layer).
made up of polyfluorene or metal chelates.
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9. Working
A voltage is applied across the
anode and cathode.
Current flows from cathode to
anode through the organic
layers.
Electrons flow to emissive
layer from the cathode.
Electrons are removed from
conductive layer leaving holes.
Holes jump into emissive layer
.
Electron and hole combine
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17. Advantages[2]
Lower Cost in the future.
Light weight & flexible plastic substrates.
Wider viewing angles.(178°)
Improved brightness (25% more than LCD)
Better power efficiency (40% less than
LCD)
Response time (<0.01 ms)
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18. Disadvantages[2]
Current cost
Life Span
Colour Balance Issue
Efficiency of Blue OLEDs
Water Damage
Outdoor Performance
Power consumption for white display
UV sensitivity.
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20. Conclusion
OLED contains stunning picture qualities and it
open a new era in display devices.
Use of proper encapsulation to prevent device
from water.
Outdoor performance can be increase by using
circular polarizer or anti-reflective coating on
cathode.
Singlet excitons will migrate with an average
diffusion length of about 20 nm followed by a
radiative or irradiative decay in Single Layer
OLED. [4]
Using Multilayer OLEDs migration and decay of
singlet excitons are also restricted resulting in
drastically improved luminous and quantum
efficiencies compared to simple single layer
devices [5] 20
1. A 4.1” QVGA active matrix display on polyethylene naphthalate (PEN) substrate
2. Array OLED
3. Optimus Maximus keyboard
HOMO and LUMO are acronyms for highest occupied molecular orbital and lowest unoccupied molecular orbital,
Viewing Angle is the angle at which the contrast ratio is still greater than 10:1.
The contrast ratio is a property of a display system, defined as the ratio of the luminance of the brightest color (white) to that of the darkest color (black) that the system is capable of producing.