Formation of Ag(Ga, In)Se2 During Selenization of Ag-Ga/In Precursor

Abstract

The substitution of Ag for Cu in Cu(Ga, In)Se 2 has been shown to optimize the bandgap of the chalcopyrite while decreasing defect density and formation temperature. The synthesis of chalcopyrite via selenization of metal precursor films with a complete substitution of Ag for Cu was studied both in-situ during selenization using high temperature x-ray diffraction and ex-situ using electron microcopy. AgInSe 2 formation at low temperatures was limited by the availability of Ag in the liquid phase resulting in the formation of Ag-deficient Ag-In-Se phases. Ga alloying into AgInSe 2 at high temperature was limited by the stability of (Ga, In) 2 Se 3 .