Carbonyl‐Mediated Hydrogen Bonding in Substituent‐Asymmetric Carbazole Phosphonic Acid Enables Robust Molecular Contacts in Blade‐Coated Inverted Perovskite Solar Cells

ABSTRACT Carbazole phosphonic acid (PACz) molecular contacts are widely used in inverted perovskite solar cells (PSCs), yet they often suffer from limited interfacial dipoles, insufficient robustness, and a trade‐off between intermolecular packing and coating uniformity under realistic solution processing. Here, we introduce a substituent‐asymmetric strategy by acetylating MeO‐4PACz to afford AcMeO‐4PACz, enabling simultaneous regulation of interfacial energetics, wetting, uniformity, and contact robustness. AcMeO‐4PACz exhibits a substantially enhanced surface‐normal dipole component (0.36 to 2.68 D) and downshifted frontier energy levels, thereby improving energetic alignment at the buried interface. The carbonyl motif mediates intermolecular hydrogen bonding, which fine‐tunes intermolecular interactions and yields a more homogeneous and solvent‐resilient molecular contact. The acetyl substitution also increases surface polarity, leading to improved precursor wetting and higher quality buried interface formation during blade coating. Consequently, blade‐coated inverted PSCs achieve a champion power conversion efficiency (PCE) of 25.57% and exhibit excellent stability under ISOS protocols (ISOS‐D‐1: 98.7% retention after 1920 h; ISOS‐D‐2: 88.0% retention after 1000 h at 65°C; ISOS‐L‐1: 99.0% retention after 1000 h under 1‐sun maximum power point tracking). This work establishes substituent asymmetry, together with carbonyl‐mediated intermolecular modulation, as an effective design strategy for processing‐resilient molecular contacts in scalable inverted PSCs.