Light-emitting diodes (leds) are commonly used light-emitting devices, which release energy and emit light through the combination of electrons and holes. Light-emitting diodes (leds), which can efficiently convert electrical energy into light energy, are widely used in modern society, such as lighting, flat panel display and medical devices. The electronic device, which appeared in 1962, could only emit low luminosity red light in its early days. Later, other monochromatic versions were developed. Today, it can emit light in visible, infrared and ultraviolet light, and the luminosity has increased to a considerable degree. And the purpose also by the initial as indicator light, display board, etc.; With the continuous progress of technology, led has been widely used in display and lighting.