Light source emission form - electric field excitation
Electroluminescence is a form of stimulated luminescence that has been used to make some indicators and signal beacons since the 1950s, but it is not suitable for general lighting.
The luminescent material is placed in a thin layer between two flat electrodes, one of which is transparent so that the generated light can appear from this electrode. This device is very similar to a capacitor, and the special phosphor used shows a local enhancement effect on the applied alternating electric field. The enhanced electric field excites the electrons in the phosphor crystal, and when the electrons reach a certain energy level, they make a transition and emit light. This is similar to the mechanism of ultraviolet light excitation of phosphors, but the way it produces free electrons is different. Its luminous efficiency is about 0.5 lumens/watt.
Recombination of the charge blocking layer at the p-n junction is believed to be the reason why silicon carbide emits light under the action of a strong electric field. This phenomenon has been known for some years. Other binary compounds have been shown to have higher luminous efficiency in surface-type electroluminescence