Alleviating Passivating Molecule Self‐Aggregation and Interfacial Non‐Radiative Recombination for High‐Performance Two‐Dimensional Metal Halide Solar Cells

Two‐dimensional metal halides paired with organic active layers form p/n interdigitated heterojunctions that offer broad potential owing to their high stability and extended spectral response. However, inherent defect states at p‐type interface frequently cause severe charge accumulation and require efficient passivation. PDAI 2 enables passivation via its strong electrostatic potential and dipole moment, yet inevitably induces severe self‐aggregation. Thus, we develop a synergistic molecular passivation strategy by introducing CyPAI with a rigid cyclopropyl group into PDAI 2 system. Owing to its weaker electrostatic potential and steric hindrance, CyPAI disrupts the hydrogen‐bond network of PDAI 2 , enabling compact and high‐coverage passivation. This strategy suppresses interfacial non‐radiative recombination, while the reconstructed interfacial dipole moment markedly accelerates the cross‐interface extraction kinetics of photogenerated carriers. Meanwhile, the ordered interdigitated p/n heterojunction constructed via nanoimprinting further enhances light trapping and interfacial contact. The optimized devices achieve a champion PCE of 24.34% and a remarkable FF of 85.36%, which is the record value for two‐dimensional metal halide solar cells so far. Notably, unencapsulated devices retain over 92% of their initial efficiency after 2,000 h of MPP tracking under 1‐sun illumination, demonstrating that this synergistic strategy effectively boosts both the high efficiency and excellent operational stability of p/n heterojunction devices.