Enhancing Efficiency and Stability of Inverted Perovskite Solar Cells via Dual‐Interface Modification with Identical Cross‐Linking Ligand

Abstract Inverted perovskite solar cells (PSCs) have great commercial prospects due to their high power conversion efficiency (PCE) and good compatibility with silicon solar cells in forming tandem cells. However, the energy loss and degradation due to the defects at the interface between perovskite and charge transport layers are still critical challenges to achieving high‐efficiency PSCs with excellent stability. In this work, a dual‐interface modification strategy effectively suppresses the defects at both the top and bottom interfaces of perovskite films, by introducing the same cross‐linkable ligand 4‐Vinylphenyl methanamine hydrochloride (VPMACl), which is activated by UV light at the interfaces of the perovskite and it can chemically interact with the perovskite layer, thereby reduce the residual strain of the perovskite and minimize interface non‐radiative recombination. The passivated PSCs with impressive PCE of 25.65% and the corresponding encapsulated devices maintained 81.5% of initial PCE after 1000 h at RH 65 ± 5% in air and 80% of initial PCE after 300 h at 85 °C in moist air, and 96.8% initial power conversion efficiency for 2000 h at maximum power point under 1 sun LED continuous illumination. This work provides an efficient strategy for improving the efficiency and stability of PSCs.