Coevaporation of Cu2ZnSnSe4 thin films

Cu 2 ZnSnSe 4 thin films grown by coevaporation are investigated in a wide temperature range and for different Se partial pressures during growth. At temperatures higher than 350 °C Sn is re-evaporating as SnSe from the surface whereas Zn is lost at temperatures higher than 430 °C. Moreover the Se partial pressure dramatically changes the Zn and Sn concentrations in the resulting film. Interrupted processes at 380 °C show that single-stage coevaporation intrinsically induces a secondary phase at the substrate/film interface.