LED, a light-emitting diode, is a solid-state semiconductor device that converts electrical energy into visible light. It can directly convert electricity into light. The heart of the LED is a semiconductor wafer, one end of which is attached to a bracket, the other end is connected to the positive pole of the power supply, so that the entire wafer is encapsulated by epoxy resin.
Semiconductor wafers consist of two parts, one of which is a P-type semiconductor, in which holes predominate, and the other end is a N-type semiconductor, mainly electrons. But when the two semiconductors connect, they form a P-N junction between them. When an electric current acts on the chip through a wire, the electrons are pushed to the P region, where the electrons recombine with holes, and then emit energy in the form of photons. That's how LED lights emit light. The wavelength of light, also known as the color of light, is determined by the material that forms the P-N junction.