LEDs (Light-Emitting Diode, referred LED) is a solid-state semiconductor can be light electronic components. Heart of the LED is a semiconductor wafer, the wafer is attached to one end of a stent, is the negative side, the other end connected to the positive power supply, so that the whole chip is epoxy encapsulated. Semiconductor chip consists of two parts, part of the P-type semiconductor, the hole in it dominates the other side is an N-type semiconductor, here is mainly electronic. But the two semiconductor connected, when between them to form a "PN junction." When the current through the wire on the chip when the electron will be pushed to the P region, in the P zone electron hole recombination, and then will be issued in the form of photon energy, which is the principle of LED light. Is the wavelength of the light color of the light, is formed by the PN junction to the materials.