Targeted passivation via ammonium benzoate for suppressing deep-level defects of doctor-bladed CH₃NH₃PbI₃ films

Large-scale processing of perovskite solar cells (PSCs) with superior performance under air conditions is deemed as an inevitable trajectory for low-cost and efficient commercial manufacturing. Herein, a strategy of targeted passivation using ammonium benzoate (C₇H₇NO₂) is developed to greatly enhance the power conversion efficiency (PCE) and stability of PSCs fabricated via large-area doctor-blading under air conditions. The conjunction of experimental and theoretical findings conclusively validates the strong interactions between the carboxylate group in C₇H₇NO₂ and the Pb²⁺ within the perovskite structure. This not only effectively neutralizes deep-level defects in the CH₃NH₃PbI₃ (MAPbI₃) perovskite film but also significantly fortifies the stability of the perovskite lattice. Consequently, PSCs with a structure of ITO/SnO₂/MAPbI₃/Spiro-OMeTAD/Ag achieve an impressive efficiency of up to 22.78%. Meanwhile, the unencapsulated devices can maintain 92.4% of their initial efficiencies after aging for 840 h. Furthermore, doctor-bladed mini modules with an area of 1.6 and 9.5 cm² exhibit PCEs of 19.73% and 18.62%, respectively.