What is the role of Gallium arsenide

What is the role of Gallium arsenide? A lot of people are not familiar with this stuff, and here's the introduction to it:

Gallium arsenide is an important semiconductor material. Ⅲ - Ⅴ clan compound semiconductor. Sphalerite lattice structure, lattice constant 5.65 x 10-10 m, melting point 1237 ℃, forbidden band width is 1.4 electron volts. Gallium arsenide entered the practical stage in 1964. Gallium arsenide resistivity can be made into more than 3 orders of magnitude higher than silicon, germanium, and a half high resistance insulation materials, used to make integrated circuit substrate, infrared detector, gamma photon detector, etc. Because its electron mobility ratio is five to six times greater than silicon, it is important to make microwave devices and high-speed digital circuits. Semiconductor devices made of gallium arsenide have advantages such as high frequency, high temperature, low temperature, low noise and strong resistance to radiation. In addition, can also be used for making transfer devices ─ ─ bulk effect device. Is gallium arsenide semiconductor materials, combines the advantages of various materials, but to use the transistor magnification small, poor heat conductivity, not suitable for making high power devices. Although the gallium arsenide has superior performance, but because it is under the high temperature decomposition, the high purity of the single crystal of reason to produce ideal ratio of chemical materials, high technical requirements.