arsenides

Arsenides are compounds that contain arsenic bonded in the form of the arsenide ion (As3−) or arsenic in a negative oxidation state within a larger compound. They commonly arise when arsenic combines with electropositive elements, particularly metals, to form binary metal arsenides or more complex arsenide phases. In inorganic chemistry, the term covers simple binaries such as aluminum arsenide (AlAs), gallium arsenide (GaAs), and indium arsenide (InAs), as well as mixed-metal arsenides with various stoichiometries.

In solid-state chemistry and materials science, arsenides are notable for their semiconducting or metallic properties. Many binary III–V arsenides (GaAs, AlAs, InAs) crystallize in zinc blende or related structures and exhibit electronic band gaps that enable electronic and optoelectronic devices. GaAs has a direct band gap of about 1.42 eV at room temperature, suitable for light emission, while InAs has a smaller gap near 0.36 eV, useful in infrared applications. Some arsenides with different metal constituents are metallic and serve as intermetallic compounds or thermoelectric materials.

Synthesis and handling: arsenides are typically prepared by high-temperature combination of arsenic with a metal, by diffusion in solid-state routes, or by chemical vapor deposition for thin films and devices. They can be sensitive to air and moisture in some forms.

Safety: arsenic compounds are toxic; the handling of arsenides requires appropriate safety measures.

See also: arsenic, arsenates, arsenites, arsenide minerals.