If the emitting layer material of the LED is an organic compound,it is known as an Organic Light Emitting Diode(OLED). To function as a semiconductor, the organic emitting material must have conjugated pi bonds.The emitting material can be a small organic molecule in a crystalline phase, or a polymer. Polymer materials can be flexible; such LEDs are known as PLEDs or FLEDs.

Compared with regular LEDs, OLEDs are lighter, and polymer LEDs can have the added benefit of being flexible. Some possible future applications of OLEDs could be:

• Inexpensive, flexible displays
• Light sources
• Wall decorations
• Luminous cloth

OLEDs have been used to produce visual displays for portable electronic devices such as cellphones, digital cameras, and MP3 players. Larger displays have been demonstrated,^]but their life expectancy is still far too short (<1,000 hours) to be practical.

Today, OLEDs operate at substantially lower efficiency than inorganic (crystalline) LEDs.