What is gallium arsenide

      Gallium arsenide, chemical formula GaAs. Black gray solid, melting point 1238℃. It is stable in the air at temperatures below 600 ° C and is impervious to non-oxidizing acids.

      Gallium arsenide is an important semiconductor material. Ⅲ – Ⅴ clan compound semiconductor. It is a sphalerite lattice structure, with a lattice constant of 5.65×10-10m, a melting point of 1237℃, and a band gap width of 1.4 electron volts. Gallium arsenide entered practical use in 1964. Gallium arsenide can be made into semi-insulated and high-resistance materials with a resistivity more than 3 orders of magnitude higher than that of silicon and germanium, which can be used to make integrated circuit substrates, infrared detectors, photon detectors, etc. Because its electron mobility is 5 ~ 6 times greater than that of silicon, it has important applications in the manufacture of microwave devices and high-speed digital circuits. Semiconductor devices made of gallium arsenide have the advantages of high frequency, high temperature and low temperature performance, low noise, strong radiation resistance and so on. In addition, it can also be used to fabricate transfer devices – body effect devices. Gallium arsenide is a semiconductor material with many advantages, but the transistor made with it has low magnification and poor thermal conductivity, so it is not suitable for making high-power devices. Although gallium arsenide has excellent properties, it is technically required to produce high purity single crystal materials with ideal chemical ratio due to its decomposition at high temperature.

      The GaAs has some better electronic features than Si, allowing it to be used in applications higher than 250 GHz. The GaAs produces less noise if the equivalent GaAs and Si elements are both operating at high frequencies. Also because the GaAs has a high crash pressure, the GaAs is better suited to operate at high power than the same Si element. Because of these features, GaAs circuits can be used in mobile phones, satellite communications, microwave point-to-point connections, radar systems, and more. GaAs have been used to make Gane diodes, microwave diodes and Gunn diodes) to emit microwaves.

      Another advantage of GaAs: It is a direct energy gap material, so it can be used for luminescence. Si is an indirect energy gap material and can only emit very faint light. (However, recent technology has been made into leds using Si and used in lasers.)