Basic Principle of LED (Light Emitting Diode)
A light emission diode consists of multiple layers of semiconductor material. When the diode is being used with direct current, the light is a product in the active layer. The light produced is separated directly in or by the reflectors. In contrast with the incandescent reflector lamps, which emit a continuous spectrum, an LED emits light in a specific color. The color of the light depends on the semiconductor material used. Two material systems are used mainly to produce LEDs with high brightness in all colors from blue to red and, through luminescence conversion, also in white. Different voltages are required to operate the diode on direct bias.