The light-emitting mechanism of incandescent lamps is that electric energy heats the light-emitting tungsten filaments to emit light. After a long time of heating, the tungsten filaments will age or even burn out. At this point, the life of the incandescent bulb is over, and the light-emitting mechanism of light-emitting diode It is determined by the special composition structure of the diode. The diode is mainly composed of a PN crystal plate, an electrode and an optical system. When a forward bias is applied to the electrode, electrons and holes are injected into the P and N regions respectively. When the balance of minority carriers and majority carriers recombine, the excess energy will be converted into light energy in the form of radiated photons. The light-emitting process includes three parts: carrier injection under forward bias, recombination radiation and light energy transmission. It can be seen that the diode mainly emits light by the continuous movement of carriers, and there is no phenomenon of aging and burnout. Its special light-emitting mechanism determines its light-emitting life as long as 50,000-100,000 hours.
