In this study, Cu(In,Ga)Se₂ thin films were prepared by a classical two-stage growth process. This process consists of the formation of Cu-In-(Ga)-Se precursors and subsequent selenization to form CuIn(Ga)Se₂. In this work, the possible interactions in Cu-In-Ga-Se systems were investigated and compared using sequentially stacked precursors, in order to modify the diffusion behavior of gallium and to get a better understanding of the Cu(In,Ga)Se₂ thin film formation. Morphology differences were observed between the different sequences, but the XRD analysis revealed the presence of graded CuIn_1–xGa_xSe₂ structure irrespective of the stacking order during the precursor formation step. The PL spectra of the Cu(In_1–x,Ga_x)Se₂ films also confirm the process of various deposition orders creates gallium gradient across the films.

evaporation, thin films, stacked precursors, selenization, structure, composition, photoluminescence.