Abstract
Precise molecular design is essential for controlling interfacial defects in carbon‐based perovskite solar cells (C‐PSCs), where recombination losses from the perovskite/hole‐transporting layer (HTL) interface and grain boundaries (GBs) limit device performance. Herein, zinc pentafluorophenyl porphyrin (ZnPF) derivatives are developed as supramolecular passivators through
p
‐selective nucleophilic aromatic substitution and incorporated into perovskite films via a green anisole‐based antisolvent strategy. Systematic variation of the aromatic substituents provided insight into the relationship between molecular structure, supramolecular packing, and defect passivation. In particular, the
p
‐phenoxy substituent in ZnPF‐2 balanced steric effects and promoted ordered molecular packing, leading to more effective interfacial passivation. This multifunctional passivation improved perovskite crystallinity and charge‐carrier transport while suppressing non‐radiative recombination and interfacial leakage currents. Consequently, ZnPF‐2‐modified devices achieved a remarkable power conversion efficiency (PCE) of 34.29% under 1000 lx illumination, while also showing consistent gains under AM 1.5G conditions and in a compositionally distinct perovskite system, supporting the transferability of the strategy. Moreover, the hydrophobic ZnPF modification improved long‐term durability, with devices preserving over 90% of their initial efficiency after 1600 h under ambient storage. This work establishes supramolecular fluorinated porphyrins as effective passivators, demonstrating how rational molecular design can contribute to sustainable indoor photovoltaic applications.