Fig. 1. (Color online) Schematic illustration of the growth pathways of FA_0.9Cs_0.1SnI₃ perovskites without additive or with PEAI–VmB1. (a) Without additive. This shows notable aggregation during the initial growth, resulting in many defects. (b) With PEAI and VmB1. This shows that the VmB1 ligands can effectively suppress aggregation, facilitating oriented growth with the assistance of PEAI in sequential growth^[11].