Imidazole Derivative Assisted Crystallization for High-Efficiency Mixed Sn–Pb Perovskite Solar Cells

Mixed Sn–Pb perovskites with narrow bandgaps and high optical absorption coefficients are promising photovoltaic materials. However, the easy oxidation of Sn²⁺ and fast crystallization of mixed Sn–Pb perovskites still limit the efficiency of mixed Sn–Pb perovskite solar cells (PSCs). Here, an imidazole derivative 2-(Aminomethyl)imidazole dihydrochloride (2-AD) to suppress the oxidation of Sn²⁺ and improve the perovskite film quality through coordination with Sn²⁺/Pb²⁺ ions is introduced. The optimized devices show a high power conversion efficiency of 22.31% with outstanding long-term illumination stability. This work provides an effective strategy to achieve efficient and stable mixed Sn–Pb PSCs.