Effects of Ag on the carrier lifetime and efficiency of (Cu1−x Ag x )2SnS3 solar cells

Abstract The effects of Ag in (Cu 1– x Ag x ) 2 SnS 3 (CATS) were investigated in terms of photoluminescence (PL) lifetime, carrier concentration, and solar cell performance with varying Ag/(Cu + Ag) ratios, x . The PL lifetime of CATS solar cells had a maximum value when x was within 7%. A similar tendency was observed for other parameters of the CATS thin films and solar cells. One of the reasons for this is that the number of non-radiative recombination centers in the CATS layer is suppressed by the sulfurization process with Ag. Therefore, even if the Ag content changes slightly in the 0%–11% range, the crystal quality is changed in CATS, resulting in a significant effect on the properties of solar cells. These investigations on the characterization and device physics can be applied to improve the efficiency of CATS solar cells.