 CIGS unit cell. Red = Cu, yellow = Se, blue = In/Ga | |
| Identifiers | |
|---|---|
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3D model (JSmol) |
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| Properties | |
| CuIn1−xGaxSe2 | |
| Density | ~5.7 g/cm3 |
| Melting point | 1,070 to 990 °C (1,960 to 1,810 °F; 1,340 to 1,260 K) (x = 0–1)[1] |
| Band gap | 1.0–1.7 eV (x = 0–1)[1] |
| Structure | |
| tetragonal,Pearson symbol tI16[1] | |
| I42d | |
a = 0.56–0.58 nm (x = 0–1),c = 1.10–1.15 nm (x = 0–1) | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Copper indium gallium (di)selenide (CIGS) is aI-III-VI2semiconductor material composed ofcopper,indium,gallium, andselenium. The material is asolid solution ofcopper indium selenide (often abbreviated "CIS") andcopper gallium selenide. It has a chemical formula of CuIn1−xGaxSe2, where the value ofx can vary from 0 (pure copper indium selenide) to 1 (pure copper gallium selenide). CIGS is atetrahedrallybonded semiconductor, with thechalcopyrite crystal structure, and abandgap varying continuously withx from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide).
CIGS is atetrahedrallybonded semiconductor, with thechalcopyrite crystal structure. Upon heating it transforms to thezincblende form and the transition temperature decreases from 1045 °C forx = 0 to 805 °C forx = 1.[1]
It is best known as the material forCIGS solar cells athin-film technology used in thephotovoltaic industry.[2] In this role, CIGS has the advantage of being able to be deposited on flexible substrate materials, producing highly flexible, lightweightsolar panels. Improvements in efficiency have made CIGS an established technology among alternative cell materials.