light-emitting diode (LED)
A light-emitting diode (LED) is a semiconductor device that can produce very bright light for a small amount of power. It consists of a p-n junction diode that emits light when electrons and holes in the semiconductor material (typically gallium arsenide phosphide) recombine at the junction. In this way it converts electrical energy applied across the junction into light. LEDs are used for display purposes in various kinds of electronic apparatus.