Reaction pathway to CZTSe formation in CdI₂

The chemical reactions between CuSe, SnSe and ZnSe and their enthalpies in molten CdI₂ in closed vacuum ampoules were investigated. Differential thermal analysis (DTA) was used for the determination of the temperatures of processes occurring in the studied mixtures. X-ray diffraction and Raman spectroscopy were performed to discover the phase changes in the long-term annealed samples at higher than peak temperatures in DTA. The occurring chemical reactions and their enthalpies were derived. The recrystallization of CZTSe in CdI₂ was investigated. The results confirmed the formation of Cu₂SnSe₃, Cu₂SnSe₄, CdSe, Cu₂CdSnSe₄, Cu₂ZnSnSe₄, and Zn_1−xCd_xSe compounds and solid solutions.