Transcript Slide 1
Introduction to:
OLED
and
PLED
Mehdi.SHarif
Content:
Organic light-emitting diodes (OLEDs) have made great progress since
the first presentation of thin film devices based on small molecule organic
materials by Tang and VanSlyke in 1987.
The OLED performance and stability have been rapidly increased over
the last years.
Also, the size of the devices is growing and several applications like
displays and general lighting are produced.
The developments for lighting applications will reach high efficiencies
and low cost production to replace fluorescent and phosphorescent
lamps.
Because of very thin active layers (several 10–100 nm), the low material
amount used for the production of OLED results in cheap and
lightweight products
An organic light emitting diode (OLED) is a light
emitting diode
In OLED the emissive electroluminescent layer is a
film of organic compounds .
There are two main families of OLEDs: those based
upon small molecules and those employing polymers.
Adding mobile ions to an OLED creates a Lightemitting Electrochemical Cell or LEC, which has a
slightly different mode of operation.
An OLED display functions without a backlight. Thus,
it can display deep black levels and can be thinner and
lighter than liquid crystal display (LCD).
Bottom or top emission:
Transparent OLEDs: it much easier to view displays
in bright sunlight
Inverted OLED:
Stacked OLEDs :
Molecules commonly used in OLEDs include organometallic chelates
chelate
Alq3
Perylene
Tris(8-hydroxyquinolinato)aluminium
Alq3 has been used as a green emitter, electron transport material and as a host for
yellow and red emitting dyes.
Polymer light-emitting diodes (PLED), also light-emitting
polymers (LEP), involve an electroluminescent conductive
polymer that emits light when connected to an external
voltage.
derivatives of poly(p-phenylene vinylene) and polyfluorene
poly(p-phenylene vinylene)
The first blue light emitting polymer diode was produced with a substituted
polyfluorene
polyfluorene
vapor thermal evaporation (VTE)
Colour patterning
• Vacuum deposition is not a suitable method for forming
thin films of polymers.
• Polymers can be processed in solution, and spin coating is
a common method of depositing thin polymer films.
• The metal cathode may still need to be deposited by
thermal evaporation in vacuum.
Lower cost in the future:
Light weight & flexible plastic
substrates:
Wider viewing angles & improved
brightness:
Better power efficiency:
LCDs filter the light emitted
Response time
Disadvantages
Lifespan: The biggest technical problem for OLEDs was the limited
lifetime of the organic materials
a lifetime of around 14,000
Color balance issues
Water damage
UV sensitivity
Manufacturers and Commercial Uses
Samsung applications
Sony applications
LG applications
15 inch 15EL9500
References:
http://en.wikipedia.org/wiki/Organic_light-emitting_diode
http://en.wikipedia.org/wiki/Chelation
http://electronics.howstuffworks.com/oled1.htm
http://www.jbibbs.com/hdtutorial/futuretech.htm
http://www.oled-display.net
Sung-Jin Kim ,Yadong Zhang,Organic Electronics 12 (2011)
492–496
M. Eritt , C. May a, K. Leo et al Thin Solid Films 518 (2010)
3042–3045