Organic LEDs (OLEDs) are thin, light-emitting devices made by placing thin layers of organic semiconductors between an anode and cathode. They were discovered in the 1970s and first used in displays in 1987. Since then, companies have developed larger OLED displays, with Sony creating the world's largest full-color OLED in 2001. OLEDs work by holes and electrons recombining in an emissive layer, causing excitons that emit light. They have advantages over LCDs like being flexible, having higher contrast ratios and faster response times, and not requiring backlights. Potential future applications include wearable displays, low-power electronics, and transparent lighting.