Indium gallium arsenide (InGaAs) is a semiconductor composed of indium, gallium and arsenic. It is used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide. InGaAs bandgap also makes it the detector material of choice in optical fiber communication at 1300 and 1550 nm. Gallium indium arsenide (GaInAs) is an alternative name for InGaAs.
Indium gallium arsenide was synthesized by T.P. Pearsall in 1976, who was the first to realize that single crystal indium gallium arsenide could be grown epitaxially on InP. Pearsall is credited with the determination of the band gap, the effective masses of electrons and holes, electron and hole mobilities and other fundamental properties of indium gallium arsenide. In 1978, Pearsall demonstrated the first high-performance p-i-n detector, and two years later the uni-traveling-carrier (utc) photodiode. Both devices are currently widely used in optical fibre telecommunications.
The indium content determines the two-dimensional charge carrier density.