Interface Engineering Based on Naphthyl Isomerization for High‐Efficiency and Stable Perovskite Solar Cells: Theoretical Simulation and Experimental Research

Perovskites have a large number of intrinsic defects and interface defects, which often lead to non-radiative recombination, and thus affect the efficiency of perovskite solar cells (PSCs). Introducing appropriate passivators between the perovskite layer and the transport layer for defect modification is crucial for improving the performance of PSCs. Herein, two positional isomers, 1-naphthylmethylammonium iodide (NMAI) and 2-naphthylmethylammonium iodide (NYAI) are designed. Based on theoretical calculation results, employing an isomeric strategy can effectively modulate the dipole moment and electronic structure of the passivators. The increase in molecular dipole moment of NYAI is beneficial for carrier separation and extraction, which can more effectively transfer charges. At the same time, the quality of perovskite films treated by NYAI has been improved to some extent, exhibiting more pronounced deep passivation effects. Therefore, the photovoltaic device modified by NYAI achieves a power conversion efficiency (PCE) of 24.39% and maintains a stability of 95.81% after 3000 h. Therefore, the isomer strategy based on naphthylamine salts is an effective way to improve the efficiency and stability of PSC devices.