Preparation and Property of Solid‐Solution Cu(In,Ga)Se ₂ ‐Cu ₂ ZnSnSe ₄ Films Obtained from the Paste Printing of Nanosized Cermet Pastes and Subsequent Selenization

Cu‐deficient Cu[(In,Ga)(Zn,Sn)]Se ₂ (CIGZTSe) films with the expected composition of 60% Cu(In,Ga)Se ₂ (CIGSe) and 20% Cu ₂ ZnSnSe ₄ (CZTSe) were prepared by paste printing of cermet nanopowder and selenization at 550–650°C for 1 h. The cermet powder contained metallic Cu, Zn, and Sn and ceramic In ₂ Se _3, and Ga ₂ Se ₃ nanopowders. The CIGZTSe films were single phase and had dense and larger grain size of 1–3 μm. Composition analyses of this CIGZTSe films were executed to demonstrate the defect behavior and the variations of electrical properties with selenization temperature. Our solar cell device made with this film as absorption layer showed power conversion efficiency of 0.86%.