Copper indium gallium selenide

Copper indium gallium selenide
CIGS unit cell. Red = Cu, yellow = Se, blue = In/Ga
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 CuIn_xGa_(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]

Structure

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]

See also

• Copper indium gallium selenide solar cells
• CZTS
• List of CIGS companies

References

1. ^ ^{a b c d} Tinoco, T.; Rincón, C.; Quintero, M.; Pérez, G. Sánchez (1991). "Phase Diagram and Optical Energy Gaps for CuInyGa1−ySe2 Alloys". Physica Status Solidi (a) 124 (2): 427. doi:10.1002/pssa.2211240206. 
2. ^ "DOE Solar Energy Technologies Program Peer Review". U.S. department of energy 2009. http://www1.eere.energy.gov/solar/review_meeting/pdfs/prm2009_contreras_cigs.pdf. Retrieved 10 February 2011.