Indium(III) selenide

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-In2Se3 is approximately 1.9 eV.

Preparation
The method of production influences the polymorph generated. For example, thin films of pure γ-In2Se3 have been produced from trimethylindium (InMe3) and hydrogen selenide via MOCVD techniques.
 * 3 H2Se + 2 In(CH3)3  ->  In2Se3  +  6 CH4

A conventional route entails heating the elements in a seal-tube:
 * 3 Se + 2 In  ->  In2Se3

General references

 * WebElements