Germanium is an important semiconductor material, which is widely used in semiconductor, aerospace measurement and control, nuclear physics detection, optical fiber communication, infrared optics, solar cells, chemical catalysts, biomedicine and other fields. According to the U.S. Geological Survey data, the proportion of global germanium end users (2015) is as follows: 30% of fiber optic fiber; 20% of infrared optical fiber; 20% of polymerization catalyst; 15% of electronic and solar devices and 15% of others (phosphor, metallurgy, and chemotherapy).
As an infrared optical material, germanium has the advantages of high infrared refractive index, wide infrared transmission band, small absorption coefficient, low dispersion, easy processing, flash and corrosion. It is especially suitable for windows, lenses, prisms and filters of thermal imagers, infrared radars and other infrared optical devices in military industry and major civil applications. High purity germanium or lithium germanium is used for gamma ray detection in astronomy Si GE10 and germanium single crystals doped with mercury, cadmium, copper and gallium are used as infrared detectors.
