One of the electroluminescence is called intrinsic electroluminescence, which was discovered by the French scientist de Strio in 1936, so it is also called de Strio effect. The light-emitting material used has a high resistivity. It is suspended in insulating media such as resin and sandwiched between two flat electrodes (one of which is often a transparent electrode). When such a system is connected with an AC power supply, the light can be transmitted from one side of the transparent electrode. The typical explanation for this phenomenon is that the electrons in the donor or trap that reach the conduction band through electric field or thermal excitation, or the electrons that enter the material from the electrode through tunneling effect, are accelerated by the electric field to obtain high enough energy, collide, ionize or excite the luminescence center, and finally lead to compound luminescence.
Another type of electroluminescence is injection electroluminescence of semiconductor p-n junction. When the semiconductor p-n junction is positively biased, electrons (holes) will be injected into the P (n) material region. In this way, the injected minority carriers will be combined with the majority carriers directly or indirectly. This composite luminescence caused by carrier injection is called injection electroluminescence. The luminescence of light-emitting diodes made of III-V semiconductor materials is this injection electroluminescence.