What are the uses of gallium and germanium as semiconductor materials

　　On July 3, according to the latest news from the Ministry of Commerce, for the purpose of safeguarding national security and interests, with the approval of the State Council, China decided to implement export controls on two key metals, gallium and germanium, starting from August 1.

　　As we all know, gallium and germanium are very important materials in semiconductor applications. But actually, what are the uses of gallium and germanium as semiconductor materials? In this article, we will focus on gallium and germanium.

　　What is Gallium?

　　Gallium is one of the members of the strategic mineral family. It is a gray-blue or silver-white metal with atomic number 31, element symbol Ga, and atomic weight of 69.723. Gallium has a low melting point but a high boiling point. Pure liquid gallium has a significant supercooling tendency, and is easily oxidized in air to form an oxide film.

　　The atomic structure of gallium includes 31 protons and electrons, and a corresponding number of neutrons. In chemical reactions, gallium atoms usually exist in a trivalent state, that is, they lose three electrons to form Ga3+ ions.

　　Industrial uses of galliumManufacturing semiconductor gallium nitride, gallium arsenide, gallium phosphide, germanium semiconductor doping element;

　　Pure gallium and low melting alloy can be used as heat exchange medium for nuclear reaction;

　　Filling material for high temperature thermometer;

　　Catalyst for diesterization in organic reaction.

　　Gallium’s industrial applications are primitive, although its unique properties may have many applications. Liquid gallium’s wide temperature range and its low vapor pressure make it useful in pyrometers and pyrometers. Gallium compounds, especially gallium arsenide, have attracted more and more attention in the electronics industry. Precise world gallium production data are not available, but production in neighboring regions is only 20 tons/year.

　　Applications of gallium

　　1.Semiconductor industry

　　Gallium plays an important role in the semiconductor industry. It is used in the manufacture of high-speed electronic devices, optoelectronic devices and solar cells. Gallium-based semiconductor materials, such as gallium arsenide (GaAs) and gallium nitride (GaN), have excellent electrical properties and high-temperature characteristics, which are suitable for the manufacture of high-frequency electronic devices and high-power electronic devices.

　　2. LED lighting

　　Gallium compounds are widely used in the manufacture of LEDs (Light Emitting Diodes). Gallium-based LEDs have the advantages of high efficiency, long life, and energy saving, and are widely used in indoor and outdoor lighting, electronic displays, and automotive lighting.

　　3.Alloy preparation

　　Gallium can form alloys with other metals to improve its characteristics and performance. For example, gallium alloys are used to make low-melting alloys such as gallium-indium alloy (often used in thermometers) and gallium-bismuth alloy (often used in fire alarm devices).

　　What is Germanium?

　　Germanium, tin and lead belong to the same group in the periodic table of elements.

　　Germanium is a chemical element with symbol Ge, atomic number 32, and atomic weight 72.64. It is located in the fourth period and group IVA of the periodic table of chemical elements.

　　Germanium element is a gray-white metalloid, shiny, hard, belonging to the carbon group, chemical properties similar to tin and silicon of the same group, insoluble in water, hydrochloric acid, dilute caustic solution, soluble in aqua regia, concentrated nitric acid or sulfuric acid, so it is soluble in molten alkali, alkali peroxide, alkali metal nitrate or carbonate, and is relatively stable in the air.

　　The atomic structure of germanium includes 32 protons and electrons, and a corresponding number of neutrons. In chemical reactions, germanium atoms usually exist in a tetravalent state, that is, they share or lose four electrons to form Ge4+ ions.

　　Industrial Uses of GermaniumGermanium has special properties in many aspects, and has extensive and important applications in semiconductors, aerospace measurement and control, nuclear physics detection, optical fiber communication, infrared optics, solar cells, chemical catalysts, biomedicine and other fields. It is an important strategic resource as well. In the electronics industry, in alloy pretreatment, in the optical industry, it can also be used as a catalyst.

　　High-purity germanium is a semiconductor material. It can be obtained by reducing high-purity germanium oxide and then extracting it by smelting. Single crystal germanium doped with a small amount of specific impurities can be used to make various transistors, rectifiers and other devices. Germanium compounds are used in the manufacture of fluorescent panels and various high refractive index glasses.

　　Germanium single crystal can be used as transistor, which is the first generation of transistor material. Germanium is used in radiation detectors and thermoelectric materials. High-purity germanium single crystal has a high refractive index. It is transparent to infrared rays, and does not pass through visible light and ultraviolet rays. Besides, it can be used as a germanium window, prism or lens for infrared light.

　　At the beginning of the 20th century, germanium was used to treat anemia, and then became the earliest semiconductor element used. The refractive index of elemental germanium is very high, and it is only transparent to infrared light, but opaque to visible light and ultraviolet light.

　　Therefore, military observers such as infrared night vision devices use pure germanium to make lenses. Compounds of germanium and niobium are superconducting materials. Germanium dioxide is a catalyst for the polymerization reaction. The glass containing germanium dioxide has high refractive index and dispersion performance, and can be used as a wide-angle camera and microscope lens. Germanium trichloride is also a new type of optical fiber material additive.

　　According to the data, since 2013, the development of the optical fiber communication industry, the continuous expansion of the application of infrared optics in the military and civilian fields, the use of solar cells in space, and the promotion of ground-based high-efficiency solar power plants have made the global demand for germanium continues to grow steadily.

　　In the early 21st century, the recovery of the global optical fiber network market, especially the optical fiber market in North America and Japan, drove the rapid growth of the optical fiber market. The annual growth rate of global optical fiber demand has exceeded 20%.

　　Applications of germanium1.Semiconductor industry

　　Germanium is an important material in the semiconductor industry. It is used in the manufacture of high-speed electronic devices and optoelectronic devices, such as high-purity germanium wafers for the manufacture of solar cells and infrared detectors.

　　Also read: The ultimate guide to high-speed PCB and housing materials

　　2. Optical fiber communication

　　Germanium optical fiber is an important material for optical fiber communication. It has a high refractive index and transparency, and can be used to manufacture optical fibers and optical fiber amplifiers in high-speed communications.

　　3. Optical applications

　　Due to the permeability of germanium to infrared radiation, it is widely used in infrared optical systems and infrared imaging technology. Germanium lenses and germanium windows are used in areas such as infrared sensors, thermal imagers and infrared laser systems.

　　Also read: Optical module – A comprehensive exploration

　　4. Chemical catalysts

　　Germanium compounds are often used as catalysts and have important applications in the chemical industry. Germanium catalysts can promote chemical reactions and are used to produce polymers, prepare organic compounds, and more.

　　ConclusionGallium and germanium, as rare metal elements, play an important role in high-tech fields, electronics industry, energy industry, etc. As technology continues to advance, so too does the demand for these two elements.