Mechanochemical P–C Bonding Strategy for Work Function Tuning in Printable Carbon–Based Perovskite Solar Cells

Abstract

In printable mesoscopic perovskite solar cells (p-MPSCs), the carbon electrode work function is a pivotal parameter governing efficient hole extraction; yet, devising environmentally benign approaches for its modulation remains a critical challenge. Herein, we report a mechanochemical strategy to construct robust P–C bonds by high-energy ball milling black phosphorus (BP) with graphite, enabling homogeneous P distribution without compromising the intrinsic graphitization degree of carbon. The tailored electronic structure leads to an optimized work function, reduced defect-state density, and improved perovskite infiltration, thereby enhancing the open-circuit voltage (V_OC) and fill factor (FF). At an optimal BP loading (3 wt%), the carbon electrode delivers a power conversion efficiency (PCE) of 17.45%, representing a 15.8% improvement over the undoped control. This work pioneers P–C bond engineering through mechanochemistry as a highly effective and scalable strategy, marking a significant advancement in the development of high-performance carbon-based perovskite solar cells.