Gallium phosphide (GaP), a phosphide of gallium, is a compound semiconductor material with an indirect band gap of 2.26 eV(300K).
Gallium phosphide wafers, <111>, diam. x thickness 50.8mm. x 0.25 - 0.55 mm - used to obtain n-type semiconductors are tellurium or sulfur. For the p-type semiconductor, zinc is used.
Gallium phosphide is used in manufacturing low-cost red, orange, and green light-emitting diodes (LEDs) with low to medium brightness. Its life is relatively short at a higher current and it is sensitive to temperature during its lifetime. It can either be used alone or along with gallium arsenide phosphide.
Green light is emitted by pure gallium phosphide at a wavelength of 555 nm. GaP doped with nitrogen emits yellow-green light at a wavelength of 565 nm. GaP doped with zinc oxide emits red light at a wavelength of 700 nm. For red and yellow light, gallium phosphide is transparent, hence GaAsP-on-GaP LEDs are better than GaAsP-on-GaAs.