A semiconductor device that converts electrical energy into light, used, for example, for the activity lights on computer disk drives. Light-emitting diodes work on the principle of electroluminescence and are highly efficient, producing little heat for the amount of light output. Acronym: LED.
Light emitted at a p-n junction is proportional to the bias current; color depends on the material used; SYN. LED.
(LED) Means of displaying symbols in electronic instruments and devices. An LED is made of semiconductor material, such as gallium arsenide phosphide, that glows when electricity is passed through it. The first digital watches and calculators had LED displays, but many later models use liquid-crystal displays.
In 1993 chemists at the University of Cambridge, England, developed LEDs from the polymer poly(p-phenylenevinyl) (PPV) that emit as much light as conventional LEDs and in a variety of colors.