Anti‐Solvent‐Free Perovskite Solar Cells Reaching 25.8% Efficiency via a D–A–π–A–D Cathode Interlayer With Strong Interfacial Dipole

ABSTRACT The non‐ideal contact at the electron transport layer/metal electrode interface remains a primary obstacle to achieving both high efficiency and operational stability in perovskite solar cells. Here, we address this challenge by developing HL136, a novel cathode interfacial material with a DMAPF–IC–IDSe–IC–DMAPF structure, to engineer the [6,6]‐phenyl‐C‐butyric acid methyl ester (PCBM)/Ag interface. Leveraging strong interfacial interactions and a pronounced dipole effect, HL136 effectively optimizes the energy‐level alignment and facilitates efficient electron extraction. For the inverted perovskite solar cells (PSCs) fabricated with HL136 (anti‐solvent‐free), we obtained a champion power conversion efficiency (PCE) of 25.8%, combined with an exceptional open‐circuit voltage (V OC ) of 1.158 V, short‐circuit current density (J SC ) of 26.5 mA cm −2 , and fill factor (FF) of 0.841. Furthermore, large‐area modules achieve a PCE of 24.7% and retain 95.5% of their initial efficiency after 1500 h of continuous illumination. This work highlights that rational cathode interfacial engineering is a potent strategy for concurrently enhancing efficiency, scalability, and long‐term durability in inverted perovskite solar cells.