OLED TECHNOLOGY
Saurabh Jain ECE- B13620802810Class No.- 94
INTRODUCTION
Uses organic light emitting diode(OLED).
Emerging Technology for displays in devices.
Main principle behind OLED technology is
electroluminescence.
Offers brighter, thinner, high contrast,
flexible displays.
WHAT IS AN OLED?
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.
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.
HISTORY (CONTD.)
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.
FEATURES
Flexibility.
Emissive Technology.
Light weight and thin.
Low power consumption.
High contrast, brighter and perfect display
from all angles.
STRUCTURE OF OLED
Substrate.
Anode.
Organic layer.
-Conductive layer (Hole Transport Layer).
made up of polyaniline or metal-phthalocyanine.
-Emissive layer( Electron Transport Layer).
made up of polyfluorene or metal chelates.
Cathode.
STRUCTURE OF OLED(FIGURE)
OLED FABRICATION
Substrate preparation.
Device deposition Deposit and pattern anode.
Pattern organic layers.
Vacuum deposit and pattern cathode.
Encapsulation.
Also involves making backplane.
OLED DEPOSITION
Organic layers can be applied to the
substrate using the following methods.
- Evaporation and shadow masking.
- Inkjet printing.
- Organic vapor phase deposition.
EVAPORATION AND SHADOW MASKING
INKJET PRINTING
WORKING PRINCIPLE
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 and light emitted.
WORKING PRINCIPLE(FIGURE)
OLED DEVICE OPERATION
Transparent substrate
Anode(ITO)
Conductive layer
Emissive layer
Cathode
LUMO
LUMO
HOMO
HOMO
eˉ
eˉ
h+
h+
h+
Light
TYPES OF OLED
Six types of OLEDs
Passive matrix OLED(PMOLED).
Active matrix OLED(AMOLED).
Transparent OLED(TOLED).
Top emitting OLED.
Flexible OLED(FOLED).
White OLED(WOLED).
PASSIVE MATRIX OLED
ACTIVE MATRIX OLED
TRANSPARENT OLED
TOP EMITTING OLED
FLEXIBLE OLED
OLED ADVANTAGES
Thinner, lighter and more flexible.
Do not require backlighting like LCDs.
Can be made to larger sizes.
Large fields of view, about 170 degrees.
Faster response time.
Brighter.
High resolution, <5μm pixel size.
OLED DISADVANTAGES
Expensive.
Lifespan.
Water damage.
Colour balance issues .
OLED VS. LCD
Greater view angle. High contrast. Faster response
time. Do not require
backlighting. Temperature(~50°C
– 80°C).
Limited view angle. Low contrast. Slow response time. Require
backlighting. Temperature(~0°C-
100°C).
OLED LCD
APPLICATIONS
Major applications of OLED technology are
OLED TV.
Mobile phones with OLED screens.
Rolltop Laptop.
OLED TV
MOBILE PHONES WITH OLED SCREEN
ROLLTOP LAPTOP
CONCLUSION
Organic Light Emitting Diodes are evolving as
the next generation displays.
As OLED display technology matures, it will
be better able to improve upon certain
existing limitations of LCD including
high power consumption
limited viewing angles
poor contrast ratios.
Thank You
Saurabh JainBPIT