Phase Transformation of CuIn_xGa_(1-x)-Se2 Powder by Milling and Heat Treatment

摘要

CuIn_xGa_(1-x)-Se2 ink and paste by milling and subsequent heat treatment to remove organic compounds contained in the thick film are to be crucial to produce dense CuIn_xGa_(1-x)-Se2 absorber layer, however, few studies has been performed to address such processes. The object of this study is to identify wet milling conditions for CuIn_xGa_(1-x)-Se2 powder and observe its phase transition and pertinent morphology change according to different heat treatments of CuIn_xGa_(1-x)-Se2. CuIn_xGa_(1-x)-Se2 powder was dispersed in planetary mill containing diethylamine as solvent and exhibited no phase transformation. CuIn_xGa_(1-x)-Se2 disappeared after annealed in air at 200 °C or more. In the case of Se-N2-H2 atmosphere, secondary phase in small portion was formed after annealed at 150 °C up to 300 °C whereas CuIn_xGa_(1-x)-Se2 was maintained above it. Dense CuIn_xGa_(1-x)-Se2 film was obtained after sintered in Se-H2-N2 at 800 °C.