Synergistic Dipole and Dual‐Passivation Enabled Highly Efficient Two‐Dimensional Perovskite Solar Cells

ABSTRACT Interface nonradiative recombination critically limits the efficiency and stability of perovskite solar cells, especially in two‐dimensional structures where compositional complexity intensifies defect formation. Here, we engineer the interface using a series of dipole molecules to achieve multifunctional passivation. The optimized molecule, 3‐(trifluoromethyl)thiophenol, uniquely combines trifluoromethyl (─CF 3 ) and thiol (‐SH) groups, enabling simultaneous defect passivation at both the perovskite surface (via Pb 2+ coordination) and the[6,6]‐Phenyl‐C61‐butyric acid methyl ester (PCBM) interface (via S···ester interaction), while its intrinsic dipole enhances charge extraction and energy‐level alignment. Moreover, the hydrophobic molecular layer effectively inhibits moisture and ion migration. Two‐dimensional perovskite solar cells (GA(MA) 5 Pb 5 I 16 ) achieve a power conversion efficiency of 22.30% with improved stability. This work provides a rational design strategy for interface molecules that integrate passivation, dipole engineering, and environmental protection, offering a viable route toward efficient and stable perovskite photovoltaics.