Material properties of Cu(In, Ga)Se2 thin films prepared by the reaction of thermally evaporated compound materials in H2Se/Ar

In this study, device quality chalcopyrite thin films were prepared by a simple and reproducible two-step growth process. The precursors were deposited by the thermal evaporation of pulverized compound materials from a single crucible onto Mo coated glass substrates at temperatures around 250 degreesC. The precursors were subsequently reacted in a controlled H2Se/Ar atmosphere at temperatures ranging between 350 degreesC and 500 degreesC. X-ray fluorescence studies revealed marginal changes in the overall bulk compositions of the films at the respective reaction temperatures, clearly demonstrating the reproducibility of the growth process. The material quality (i.e., surface morphologies, formation of crystalline phases and in-depth compositional uniformity) of the films was compared at the respective reaction temperatures in order to determine optimum processing parameters.