View source for Copper indium gallium selenide

{{chembox
| verifiedrevid =
| ImageFile = Chalcopyrite-unit-cell-3D-balls.png
| ImageCaption = CIGS unit cell. Red = Cu, yellow = Se, blue = In/Ga
| IUPACName =
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|<del.>
chemspider}}
| ChemSpiderID = 24774055
| InChI =
| InChIKey =
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI =
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey =
| CASNo = 12018-95-0
| CASNo_Ref = (CuInSe<sub>2</sub>)
| PubChem =
| RTECS =
| SMILES =
}}
|Section2={{Chembox Properties
| Formula =CuIn<sub>1−''x''</sub>Ga<sub>''x''</sub>Se<sub>2</sub>
| MolarMass =
| Appearance =
| Density = ~5.7 g/cm<sup>3</sup>
| Solubility =
| MeltingPtC = 1070 to 990
| MeltingPt_notes = (''x'' = 0–1)<ref name=str/>
| BoilingPt =
| BandGap = 1.0–1.7 eV (''x'' = 0–1)<ref name=str/>
| ElectronMobility =
| ThermalConductivity =
| RefractIndex =
}}
|Section3={{Chembox Structure
| MolShape =
| CrystalStruct =tetragonal, [[Pearson symbol]] tI16 <ref name=str>{{cite journal |doi=10.1002/pssa.2211240206 |title=Phase Diagram and Optical Energy Gaps for CuIn<sub>''y''</sub>Ga<sub>1−''y''</sub>Se<sub>2</sub> Alloys |year=1991 |last1=Tinoco |first1=T. |last2=Rincón |first2=C. |last3=Quintero |first3=M. |last4=Pérez |first4=G. Sánchez |journal=Physica Status Solidi A |volume=124 |issue=2 |pages=427 |bibcode=1991PSSAR.124..427T}}</ref>
| SpaceGroup = I{{overline|4}}2d
| LattConst_a = 0.56–0.58 nm (''x'' = 0–1)
| LattConst_c = 1.10–1.15 nm (''x'' = 0–1)
| Coordination =
| Dipole =
}}
}}
'''Copper indium gallium (di)selenide''' ('''CIGS''') is a [[Alkali metal|I]]-[[Group 3 element|III]]-[[Group 6 element|VI]]<sub>2</sub> [[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<sub>1−''x''</sub>Ga<sub>''x''</sub>Se<sub>2</sub>, where the value of ''x'' can vary from 0 (pure copper indium selenide) to 1 (pure copper gallium selenide). CIGS is a [[tetrahedral]]ly [[chemical bond|bond]]ed semiconductor, with the [[chalcopyrite]] crystal structure, and a [[bandgap]] varying continuously with ''x'' from about 1.0&nbsp;eV (for copper indium selenide) to about 1.7&nbsp;eV (for copper gallium selenide).
==Structure==
CIGS is a [[tetrahedral]]ly [[chemical bond|bond]]ed semiconductor, with the [[chalcopyrite]] crystal structure. Upon heating it transforms to the [[zincblende]] form and the transition temperature decreases from 1045&nbsp;°C for ''x'' = 0 to 805&nbsp;°C for ''x'' = 1.<ref name=str/>
== Applications ==
It is best known as the material for [[Copper indium gallium selenide solar cells|CIGS solar cells]] a [[thin-film solar cells|thin-film technology]] used in the [[photovoltaic]] industry.<ref>{{Cite web|url=http://www1.eere.energy.gov/solar/review_meeting/pdfs/prm2009_contreras_cigs.pdf|title=DOE Solar Energy Technologies Program Peer Review|publisher=U.S. department of energy 2009|access-date=10 February 2011}}</ref> In this role, CIGS has the advantage of being able to be deposited on flexible substrate materials, producing highly flexible, lightweight [[solar panel]]s. Improvements in efficiency have made CIGS an established technology among alternative cell materials.
==See also==
*[[Copper indium gallium selenide solar cells]]
*[[CZTS]]
*[[List of CIGS companies]]
==References==
{{reflist}}
{{Selenides}}
[[Category:Semiconductor materials]]
[[Category:Copper(I) compounds]]
[[Category:Indium compounds]]
[[Category:Gallium compounds]]
[[Category:Selenides]]
[[Category:Renewable energy]]
[[Category:Dichalcogenides]]