Fig. 9. (a) Variation in the bandgap of Sn–Pb perovskite with changes in the Pb and Sn ratio in the B site. (b) Schematic illustrating how the bandgap is formed in Pb–Sn alloy perovskite. (c) Substituting Pb with Sn in perovskite leads to the formation of defect sites, causing nonradiative voltage loss. (d) Time-resolved photoluminescence spectra are obtained for FA0.75Cs0.25SnxPb1−xI3 perovskite layers with varying Sn amounts.132 (b) Ref. 133. (c) Ref. 134. (d) Ref. 135.
