Interfacial Field‐Effect Enabling High‐Performance Perovskite Photovoltaics

Currently, the power conversion efficiency (PCE) of inverted perovskite solar cells (PSCs) is still limited by reduced open-circuit voltage (V_OC), due to defect-induced charge recombination. Most studies focus on defect passivation and improving carrier transport through introducing passivating molecules or macroscopic physical fields. Herein, to mitigate energy level mismatch and recombination losses induced by interface defects, an interface electric-field passivation is introduced, employing the ordered arrangement of the dipole molecule benzenesulfonyl chloride (BC). An enhanced V_OC is achieved without the introduction of an external physical field, owing to the interfacial dipole field effect and chemical passivation by BC. Subsequently, an inverted device with a PCE of 25.41% is obtained, alongside exceptional stability, retaining 95% of the initial efficiency after 1157 h. This work demonstrates the effective dipole-induced interfacial field-effect passivation in inverted PSCs and contributes to further advancements in the efficiency and stability of inverted devices.