Comparative study of the influence of two distinct sulfurization ramping rates on the properties of Cu2ZnSnS4 thin films

► The ramping rate of sulfurization of CZTS precursors with high Sn content has been studied. ► Fast ramping at 21 °C/min resulted in the degraded CZTS films after sulfurization with a bubble-like surface. ► Slow ramping at 2 °C/min can remove the excessive Sn in the films and elevate the crystalline quality of CZTS films.