Wide band-gap tuning in Sn-based hybrid perovskites through cation replacement: the FA1−xMAxSnBr3 mixed system

Abstract

We report the synthesis and characterization of the first Sn-based mixed system, namely FA_1−xMA_xSnBr₃ (0 ≤ x ≤ 1), providing also the first study of the FASnBr₃ hybrid perovskite. The results indicate the formation of a continuous solid solution between the two end members with a huge modulation of the band gap induced by cation replacement. These results suggest the key role of protonated amines in the electronic structure in tin-based systems and a new and effective way of tuning the band gap.