Quantitative analysis of grain boundary attributes and their impact on device performance in perovskite solar cells based on 3D modeling

The complex generation, transport, and recombination behaviors of charge carriers in perovskite solar cells are fundamentally governed by the diverse orientations, locations, and defect properties of grain boundaries (GBs) in the absorber layer. Herein, we employ 3D TCAD simulations to quantitatively evaluate the correlation between these GB characteristics and device performance metrics, including power conversion efficiency, fill factor, and open-circuit voltage (VOC). We successfully decouple the primary factors and quantify their relative contributions to optoelectronic performance. Our findings demonstrate that transverse grain boundaries (TGBs) form electrostatic barriers that induce severe carrier accumulation and resistive losses. Conversely, vertical grain boundaries primarily induce non-radiative recombination losses while still enabling charge extraction through the grain interior. Notably, owing to the Beer–Lambert carrier generation profile, TGBs adjacent to the hole transport layer induce severe efficiency degradation, with donor-type traps exhibiting a remarkably higher spatial sensitivity than acceptor states. This study provides critical theoretical guidelines for optimizing perovskite film crystallization, interface engineering, and targeted defect passivation.