OLED ( Organic Light – Emitting Diode )

• First developed in the early 1950s in France

• They applied high alternating voltages in air to materials such as acridine orange, either deposited on or dissolved in cellulose or cellophane thin films.

• 1960s AC-driven electroluminescent cells using doped anthracene was developed.

• In 1987 Chin Tang and Van Slyke introduced the first light emitting diodes from thin organic layers.

• In 1990 electroluminescence in polymers was discovered.

Types of OLEDs

1. Passive OLEDs : The organic layer is between strips of cathode and anode that run perpendicular. The intersections form the pixels. Easy to make. Use more power and are best for small screens.

2. Active OLEDs : Full layers of cathode and anode. Anode overlays a thin film transistor (TFT). Requires less power. Higher refresh rates and are suitable for large screens.

• In some ways, OLEDs are better for display devices than LCDs. There are also ways LCDs are better.

• OLEDs can make more different colors at different levels of brightness than LEDs. Unlike LCDs their colors do not change when viewed at an angle.

• They are also much cheaper to make.

• Most LCDs have to have an LED used as a backlight to be visible. LCDs also need to use filters to work properly. Because of backlighting and filtering, OLEDs use far less power than LCDs for the amount of light made.

• OLEDs also react faster to changes in electricity. They turn on and off much faster than LCDs.

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• TVs• Cell Phone screens • Computer Screens• Keyboards (Optimus Maximus)• Lights• Portable Device displays