Vision Institute of Technology Seminar On OLED Technology

Vision Institute of Technology Seminar On OLED Technology Submitted By: Satyam Yadav

Content � Introduction � What is an OLED? � History � Features � Structure of OLED(Figure) � OLED Fabrication � OLED Deposition � Types of OLED � OLED Advantages � OLED Disadvantages � Applications � Conclusion � References

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(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.

Colour Generation �Different approaches for fabricating red, green and blue pixels. - Red, green and blue individual pixels. - White emitter and colour filters. - Blue emitter and colour converters. - Stacked OLED

Colour Generation(figure)

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 eˉ LUMO Light HOMO h+ Cathode h+ h+

Types of OLED Six types of OLEDs q Passive matrix OLED(PMOLED). q Active matrix OLED(AMOLED). q Transparent OLED(TOLED). q Top emitting OLED. q Flexible OLED(FOLED). q White OLED(WOLED).

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.

Applications Major applications of OLED technology are �OLED TV. �Mobile phones with OLED screens. �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.

References �www. google. com �www. wikipedia. com �www. studymafia. org �www. pptplanet. com

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