Fig. 1. Schematic of crystal structure of perovskite

Fig. 2. Structure of perovskite solar cells

Fig. 3. Data analysis of BA₂MA₃Sn₄I₁₃ perovskite films and their devices from different solvents

Fig. 4. Data analysis of photoluminescence of perovskite films with and without ionic liquid treatment

Fig. 5. Data analysis of performance of perovskite films and their devices prepared with BAI and BAAc

Fig. 6. Data analysis of performance of single crystal BM₂MA_n-1Pb_nI_3n+1 (n=1, 2, 3, 4) perovskite films