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Gallium arsenide contains 48.2% gallium and 51.8% arsenic and is considered an intermetallic compound. It occurs as cubic crystals with a dark gray metallic sheen. Gallium arsenide is electroluminescent in infrared light. Gallium arsenide readily reacts with oxygen in air, forming a mixture of oxides of gallium and arsenic on the crystal surface. Gallium arsenide presents the following properties: hardness, 4.5; thermal expansion coefficient, 5.9×106; thermal conductivity, 0.52Wunits; specific heat, 0.086 cal/g/ ℃; intrinsic electron concentration, 107; energy gap at room temperature, 1.38 eV; electron mobility, 8800 cm2/V/s; effective mass for electrons, 0.06m0; lattice constant,5.6–54 AO; dielectric constant, 11.1; intrinsic resistivity at 300K＝3.7×108Ωcm; electron lattice mobility at 300K＝ 10,000 cm2/V/s; intrinsic charge density at 300K＝1.4 106 cm-3; electron diffusion constant at 300K＝310 cm2/s; and hole diffusion constant＝11.5 cm2/s. Garlic odor when moistened. Finely divided gallium arsenide can react vigorously with steam, energetic acids, and oxidizers to evolve arsine gas, and can release arsenic fumes when heated to decomposition. The molten form attacks quartz.

용도In semiconductor applications (transistors, solar cells, lasers).Gallium arsenide is among the most widely used intermetallic semiconductor components (Harrison, 1986; McIntyr and Sherin, 1989). Gallium arsenide is also incorporated into light-emitting diodes and photovoltaic cells, while gallium alloys are used for dental amalgam as a low toxicity replacement for mercury.

일반 설명Dark gray crystals with a metallic greenish-blue sheen or gray powder. Melting point 85.6°F (29.78°C).

Gallium arsenide is prepared by passing a mixture of arsenic vapor and hydrogen over gallium(III) oxide heated at 600°C: Ga2O3 + 2As + 3H2 2GaAs + 3H2OThe molten material attacks quartz. Therefore, quartz boats coated with carbon by pyrolytic decomposition of methane should be used in refining the compound to obtain high purity material. Gallium arsenide is produced in polycrystalline form as high purity, single crystals for electronic applications. It is produced as ingots or alloys, combined with indium arsenide or gallium phosphide, for semiconductor applications.