Crystal Structure of Gallium arsenide

Gallium arsenide (GaAs) is a III-V compound semiconductor material. It consists of the metal atoms gallium (Ga) and arsenic (As). GaAs is used in photovoltaic cells, tunnel diodes, lasers, semiconductors and MESFET transistors. Gallium arsenide crystals consist of two sublattices, each of which is face-centred cubic (fcc) with the diagonal halves offset from each other. This crystal structure is called cubic sphalerite or zinc sphalerite. GaAs is crystallised in the cubic F̅43m space group. Ga³⁺ is bonded to four equivalent As³- atoms to form the co-angle GaAs₄ tetrahedra. All Ga-As bonds are 2.49 Å. As³- is bonded to four equivalent Ga³⁺ atoms to form the co-angled AsGa₄ tetrahedra.