In Situ Dual-Interface Passivation Strategy Enables the Efficiency of Formamidinium Perovskite Solar Cells over 25%

Currently, approaches to further improve device efficiencies tend to focus on the passivation of interfacial defects. Although various strategies have been developed to mitigate these defects, many involve complex and time-consuming post-treatment processes, thereby hindering their widespread adoption in commercial applications.

In this work, we develop a concise but efficient in situ dual-interface passivation strategy wherein 1-butyl-3-methylimidazolium methanesulfonate (MS) is employed as a precursor additive. During perovskite crystallization, MS can either be enriched downward through precipitation with SnO2, or can be aggregated upward through lattice extrusion. These self-assembled MS species play a significant role in passivating the defect interfaces, thereby reducing non-radiative recombination losses, and promoting more efficient charge extraction.