Cu2ZnSnSe4 thin films grown by molecular beam epitaxy

Abstract Cu 2 ZnSnSe 4 has a potential for photovoltaic cells but the performances must be improved. Here, we report on CZTSe grown by molecular beam epitaxy. A smooth 2D growth mode was maintained during the deposition except for the early stage of the deposition where nanometer islands formed. This initial 3D growth is attributed to the formation of CuGaSe 2 and CuGaZnSe 3 detected by X-ray diffraction. Reflection of high energy diffraction oscillations, correlated to the growth rate, were obtained. The Cu 2 ZnSnSe 4 film grew epitaxially on GaAs with its c-axis oriented along the GaAs[001] growth direction and Cu 2 ZnSnSe 4 (001)[110] parallel to GaAs(001)[110].