[Ad]LED means the light emitting diode. Diode means the equipment which will have two electrodes. When we send the energy to diode it transfers from the higher energy to lower energy. This energy difference is appeared in the form of the light. Such that the light is emitted from the diode and this is passed from various chemicals so that it emits different colors.
Gallium Arsenide (GaAs) : Infrared Light
Gallium Arsenide Phosphorus (GaAsP) : Red or Yellow light
Gallium Phosphorous (GaP) : Red or Green light
Aluminum Gallium Phosphide (AlGaP) : Green Light
For the great Invention. The scientists who have invented this component has awarded with Nobel Prize In 2014. This is invented by the Japanese scientists named Akasaki, Aamano Nakaramura.