Electroluminescence is light produced with little or no heat by passing an electric current through a phosphorescent substance. Such a substance contains phosphors, chemicals that absorb energy and give off visible light for some time after the energy source is removed.
Manufacturers use electroluminescent systems primarily to light certain displays from behind. Such displays include signs, control panels on electronic devices, and aircraft and automobile instrument panels. An electroluminescent system generally consists of a layer of phosphors between a metal plate and a transparent coating that conducts electric current. When pulsating current (current that changes value at intervals) flows through the plate and coating, the phosphors glow.
In 1907, Henry Joseph Round, an English electronics engineer, was the first person to observe electroluminescence, in silicon carbide. Georges Destriau, a French scientist working in the laboratory of the physicists Pierre and Marie Curie, was probably the first person to use the term electroluminescence. He observed the phenomenon in zinc sulfide powder in 1936. Today, electroluminescent panels are commonly made using zinc sulfide doped (treated) with small amounts of copper or manganese.
See also Phosphorescence.
