Stable tin perovskite solar cells developed via additive engineering

Tin perovskite solar cells (TPSCs) are promising for lead-free perovskite solar cells (PSCs) and have led to extensive research; however, the poor crystallinity and chemical stability of tin perovskites are two issues that prevent stable TPSCs. In this study, we outline a new process that addresses these issues by using tin(II) acetate (Sn(Ac) 2 ) in place of the conventional SnF 2 precursor additive. Compared with SnF 2 , Sn(Ac) 2 improves the crystallinity and stability of tin perovskite with fewer defects and better charge extraction. Using this process, we developed a device that has a higher external quantum efficiency for charge extraction compared with the control devices and a power conversion efficiency of 9.93%, which maintained more than 90% of its initial efficiency after 1000 h operation at the maximum power point under standard AM 1.5G solar illumination.