Indium(III) selenide is a compound of indium and selenium. It has potential for use in photovoltaic devices and has been the subject of extensive research. The two most common phases, α and β, have a layered structure, while γ has a "defect wurtzite structure." In all, five polymorphs are known: α, β, γ, δ, κ. The α-β phase transition is accompanied by a change in electrical conductivity. The band gap of γ-InSe is approximately 1.9 eV.