Gas Molecule Assisted All‐Inorganic Dual‐Interface Passivation Strategy for High‐Performance Perovskite Solar Cells

Abstract

Abstract The trap states at both the upper and bottom interfaces of perovskite layers significantly impact non‐radiative carrier recombination. The widely used solvent‐based passivation methods result in the disordered distribution of surface components, posing challenges for the commercial application of large‐area perovskite solar cells (PSCs). To address this issue, a novel NH3 gas‐assisted all‐inorganic dual‐interfaces passivation strategy is proposed. Through the gas treatment of the perovskite surface, NH3 molecules significantly enhanced the iodine vacancy formation energy (1.54 eV) and bonded with uncoordinated Pb2+ to achieve non‐destructive passivation. Meanwhile, the reduction of the film defect states is accompanied by a decrease in the work function, which promotes carrier transport between the interface. Further, a stable passivation layer is constructed to manage the bottom interfacial defects using inorganic potassium tripolyphosphate (PT), whose ─P═O group effectively mitigated the charged defects and lowered the carrier transport barriers and nucleation barriers of PVK, while the gradient distribution of K+ improved the crystalline quality of PVK film. Based on the dual‐interface synergistic effect, the optimal MA‐contained PSCs with an effective area of 0.1 cm2 achieved an efficiency of 24.51% and can maintain 90% of the initial value after aging (10−20% RH and 20 °C) for 2000 h.

Keywords

• all‐inorganic treatment
• dual‐interface passivation
• gas‐assisted passivation
• perovskite solar cells