Copper indium gallium selenide | |
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CIGS unit cell. Red = Cu, yellow = Se, blue = In/Ga
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Identifiers | |
CAS number | 12018-95-0(CuInSe2) |
Properties | |
Molecular formula | CuInxGa(1-x)Se2 |
Density | ~5.7 g/cm3 |
Melting point |
1070-990 °C(x=0–1)[1] |
Band gap | 1.7–1.0 eV (x=0–1)[1] |
Structure | |
Crystal structure | tetragonal, Pearson symbol tI16 [1] |
Space group | I42d |
Lattice constant | a = 0.56–0.58 nm (x=0–1), c = 1.10–1.15 nm (x=0–1) |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
Infobox references |
Copper indium gallium (di)selenide (CIGS) is a I-III-VI2 semiconductor material composed of copper, indium, gallium, and selenium. The material is a solid solution of copper indium selenide (often abbreviated "CIS") and copper gallium selenide. It has a chemical formula of CuInxGa(1-x)Se2 where the value of x can vary from 1 (pure copper indium selenide) to 0 (pure copper gallium selenide). CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure, and a bandgap varying continuously with x from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide). It is used as light absorber material for thin-film solar cells.[2]
CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure. Upon heating it transforms to the zincblende form and the transition temperature decreases from to 1045 °C for x=0 to 805 °C for x=1.[1]