light-emitting diode (LED)

https://doi.org/10.1351/goldbook.LT07414
semiconductor (often a combination of gallium, arsenic and phosphorous or gallium and nitrogen) containing an n region (where electrons are more numerous than positive charges) separated from a p region (where positive charges are more numerous than negative charges). Upon application of a voltage, charges move and emission of ultraviolet, visible or infrared radiation is produced each time a charge recombination takes place. Although a LED emits incoherent monochromatic light, normally a very narrow frequency range is obtained.
Notes:
  1. This effect is a form of @E01966@.
  2. The colour depends on the semi-conducting material used, and can be @UT07492@, @VT07496@ or @IT07399@.
  3. Organic light-emitting devices (OLEDs) contain diodes made of small molecules or made of @M03667@ materials. The latter are sometimes called PLEDs.
Source:
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 364 (https://doi.org/10.1351/pac200779030293)