Pharmacophore‐Guided Interfacial Ligands Co‐Optimize Charge Extraction and Heat Dissipation in Semitransparent Perovskite Solar Cells

ABSTRACT Semitransparent perovskite solar cells (ST‐PSCs) for building‐integrated photovoltaics (BIPV) face severe performance trade‐offs when the absorber is thinned to achieve high average visible transmittance (AVT). Thinner absorbers lead to a higher density of interfacial defects, stronger optical scattering, and faster thermal degradation resulting from inefficient heat dissipation. To overcome these interconnected challenges, we introduce a pharmacophore‐guided molecular design strategy using dexamethasone (Dex). The conformationally rigid scaffold of Dex spatially arranges carbonyl, hydroxyl, and 9α‐fluoro groups to enable multi‐point molecular recognition at perovskite heterointerfaces. This precise functional group arrangement simultaneously passivates Pb 2+ and halide defects while enabling high‐quality, pinhole‐minimized films. Meanwhile, an inward‐oriented interfacial dipole optimizes band alignment and accelerates hole extraction, while concurrently enhancing thermal transport by reducing the interfacial thermal resistance. Density functional theory (DFT) and opto‐electro‐thermal (OET) modeling quantitatively demonstrate suppressed nonradiative recombination and interfacial heat generation. Consequently, optimized ST‐PSCs with ∼150 nm absorbers achieve a high open‐circuit voltage of 1.165 V and power conversion efficiency of 15.26% at 20.88% AVT (LUE ≈ 3.19%), with T 80 > 1000 h at 80°C in nitrogen. This work establishes pharmacophore‐guided interfaces as a versatile materials design paradigm for synchronizing optical, electrical, and thermal management in ultrathin PVs.