The terminal voltage of p-n junction forms a certain potential barrier. When the positive bias voltage is added, the potential barrier decreases and most carriers in p-region and n-region spread to each other. Since the electron mobility is much higher than the hole mobility, a large number of electrons will spread to the P region, forming the injection of a few carriers in the P region. These electrons recombine with the holes in the valence band and the resulting energy is released as light energy. This is how the p-n junction gives off light.
1. Small power specifications: straw hat/helmet, round head, concave, oval, square (2*3*4) bullet, flat head, (3/5/ flat head/bread) piranha, etc.
2. SMD patches are generally divided into (3020/3528/5050 these are the front light) /1016/1024 and so on. These are the side light sources.
3. High-power leds cannot be classified into patch series, because their power and current use are not the same, and the photoelectric parameters are quite different. Single high-power LED light source without heat dissipation base (generally hexagonal aluminum base), its appearance is not too different from the ordinary patch, high-power LED light source is circular, the packaging method is basically the same as SMD patch, but with SMD patch in use conditions/environment/effect are essentially different.