Interfacial Hydrophilization‐Assisted Buried‐Interface Reconstruction for Efficient Inverted Perovskite Solar Cells

ABSTRACT Carbazole‐based self‐assembled monolayers (SAMs) stand out as competitive hole‐transport materials for inverted perovskite solar cells (PSCs), benefiting from their low‐temperature processing and robust operational stability. Nevertheless, intrinsic SAM aggregation and surface hydrophobicity hinder perovskite precursor wetting, trigger uneven buried‐interface nucleation, and worsen interfacial contact, limiting device performance improvement. Herein, two fluorinated phosphonic‐acid molecules, namely FPA‐Ph and FPA‐Py, are utilized to reconstruct the buried SAM/perovskite interface. Both modifiers improve the wettability of the SAM surface and modulate the local interfacial environment via interactions with the SAM and perovskite components. Relative to FPA‐Ph, the extra pyridinic‐N sites in FPA‐Py further boost surface wettability and strengthen Pb 2+ coordination, concurrently generating a smoother and more homogeneous SAM layer. These synergistic effects promote the formation of compact perovskite films, favorable interfacial energetics, and optimized carrier dynamics. Consequently, FPA‐Py‐modified PSCs deliver a champion efficiency of 26.53% while possessing exceptional operational stability against high humidity, elevated temperature, and continuous illumination. This work demonstrates hydrophilization‐assisted molecular post‐treatment as an effective approach to buried‐interface reconstruction and provides rational molecular‐design guidance for the scalable fabrication of inverted PSCs.