. Emission is made of a structure called a pn junction with the semiconductor is performed by directly converting the light energy to the energy of the electron in the “ light-emitting diode , and exercise heat macroscopically does not require intervention . holes and electrons injected into the semiconductor from electrodes flows ( the valence band and conduction band ) energy band different , recombine across the band gap in the pn junction near . recombination sometimes , the wavelength of the light . emission energy corresponds substantially band gap ( forbidden band width ) is emitted as light is determined by the band gap of the material , it various visible range , to the ultraviolet region of the infrared region by this the resulting light emission , and low degree of freedom with a single -color basis. however, can represent any color ( full color ) by using a light emitting diode ( three primary colors of light ) blue , red, green , and blue or ultraviolet by applying a fluorescent paint on the surface of the light-emitting diode , light emitting diodes of various neutral colors such as warm white , and white are also produced . ( from wiki ) “