Phase Transformation of CuInxGa1-x-Se-2 Powder by Milling and Heat Treatment

Abstract

CuInxGa1-x-Se-2 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 CuInxGa1-x-Se-2 absorber layer, however, few studies has been performed to address such processes. The object of this study is to identify wet milling conditions for CuInxGa1-x-Se-2 powder and observe its phase transition and pertinent morphology change according to different heat treatments of CuInxGa1-x-Se-2. CuInxGa1-x-Se-2 powder was dispersed in planetary mill containing diethylamine as solvent and exhibited no phase transformation. CuInxGa1-x-Se-2 disappeared after annealed in air at 200 degrees C or more. In the case of Se. N-2-H-2 atmosphere, secondary phase in small portion was formed after annealed at 150 degrees C up to 300 degrees C whereas CuInxGa1-x-Se-2 was maintained above it. Dense CuInxGa1-x-Se-2 film was obtained after sintered in Se-H-2-N-2 at 800 degrees C.