Indium(III) selenide is a compound of indium and selenium. It has potential for use in photovoltaic devices and it has been the subject of extensive research. The two most common forms α- and β- have "defect wurtzite structures", however there are five known forms (α, β, γ, δ, κ) The α- β phase transition is accompanied by a change from metallic conduction. The band-gap of γ-In2Se3 is approximately 1.9 eV. The crystalline form of a sample can depend on the method of production, for example thin films of pure γ-In2Se3 have been produced from trimethylindium, InMe3, and hydrogen selenide, H2Se, using MOCVD techniques