May 15 2014
Electroluminescence is, as the name suggests, an electrical and an optical phenomenon. Electroluminescence is the characteristic of a material to emit light when an electric current is passed through it, or when subjected to a strong electric field.
Electroluminescence is different from black body emission, chemiluminescence, or even mechanoluminescence.
Electroluminescence is the principle behind the construction of LEDs, automobile displays, and night lamps. Semiconductors are the most predominantly available electroluminescent materials.
Basic Principle
The mechanism behind electroluminescence is the radiative recombination, or spontaneous emission. When a semiconductor is subjected to an electric current, recombination of the electron hole pairs takes place. These excited electrons release energy, in the form of photons, resulting in the emission of light.
Some examples of electroluminescent materials are thin film zinc sulfide doped with manganese, III and V class semiconductors, and inorganic semiconductors.
Applications
Electroluminescence finds a number of applications, such as:
- LEDs
- Backlights
- Liquid crystal displays
- Night lamps
- Electroluminescent lighting
Sources and Further Reading