Aromatic‐Substituted Carbazole Monolayers: Self‐Assembly Optimization for Efficient Inverted Perovskite Solar Cells

ABSTRACT Self‐assembled monolayers (SAMs) offer transformative potential as hole‐transporting layers (HTLs) in inverted perovskite solar cells (IPSCs) through lossless contact engineering and suppressed interfacial recombination. To address persistent challenges of molecular aggregation, inadequate wettability, and limited durability, we pioneered a groundbreaking fluorine‐substituted aromatic carbazole‐based SAM molecule: (3‐(3,6‐bis(3‐fluoro‐4‐methoxy‐phenyl)‐9H‐carbazol‐9‐yl)‐propyl)phosphonic acid (F‐MeO‐3PABCz). This design achieves three breakthroughs: (1) defect passivation via optimized perovskite crystallization and energy‐level alignment, eliminating nonradiative recombination at the buried interface; (2) enhanced hole extraction/transport through directed molecular assembly; and (3) superior stability via fluorine‐induced hydrophobicity and aggregation resistance. The result is an impressive‐breaking champion power conversion efficiency (PCE) of 26.21% (certified 25.76%), surpassing commercial 4PACz‐based devices (24.37%) by a significant margin. Accelerated aging tests confirm F‐MeO‐3PABCz's exceptional operational longevity, outperforming conventional HTLs under thermal and humidity stress. This work establishes a paradigm for SAM engineering by integrating fluorine substitution, aromatic rigidity, and phosphonic acid anchoring, paving the way for next‐generation high‐efficiency IPSCs with industrial‐grade durability.