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The Bridgman method is a popular way of producing certain semiconductor crystals such as gallium arsenide, for which the Czochralski method is more difficult. The process can reliably produce single-crystal ingots, but does not necessarily result in uniform properties through the crystal.
The carrier density is important for semiconductors, where it is an important quantity for the process of chemical doping.Using band theory, the electron density, is number of electrons per unit volume in the conduction band.
Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits , monolithic microwave integrated circuits , infrared light-emitting diodes , laser diodes , solar cells and optical windows.
In this technique heterostructures such as gallium arsenide / aluminum gallium arsenide (GaAs/AlGaAs) distributed Bragg reflectors (DBRs) are grown and then transferred to polished optical surfaces, resulting in high-performance single-crystal optical coatings on arbitrary, including curved, substrates.
Gallium reacts with ammonia at 1050 °C to form gallium nitride, GaN. Gallium also forms binary compounds with phosphorus, arsenic, and antimony: gallium phosphide (GaP), gallium arsenide (GaAs), and gallium antimonide (GaSb). These compounds have the same structure as ZnS, and have important semiconducting properties.
Organogallium compounds can be synthesized by transmetallation, for example the reaction of gallium metal with dimethylmercury: 2Ga + 3Me 2 Hg → 2Me 3 Ga + 3 Hg. or via organolithium compounds or Grignards: GaCl 3 + 3MeMgBr → Me 3 Ga + 3MgBrCl. The electron-deficient nature of gallium can be removed by complex formation, for example
In the example of gallium and arsenic, single-crystal gallium arsenide is formed. When evaporation sources such as copper or gold are used, the gaseous elements impinging on the surface may be adsorbed (after a time window where the impinging atoms will hop around the surface) or reflected. Atoms on the surface may also desorb.
Gallium arsenide (GaAs) is also widely used in high-speed devices but so far, it has been difficult to form large-diameter boules of this material, limiting the wafer diameter to sizes significantly smaller than silicon wafers thus making mass production of GaAs devices significantly more expensive than silicon.