Referred to as a light emitting diode LED. The gallium (Ga) and arsenic (AS), a diode phosphorus (P) is made ​​of a compound, when the electron and hole recombination can radiate visible light, which can be used to form a light emitting diode. As in the circuit and the instrument lights, or the composition of text or digital display. GaAs diode glows red phosphorus, gallium phosphide diode glows green, yellow hair SiC diodes.