ChargeFabrica: a python-based finite difference multidimensional electro-ionic drift diffusion simulator applied to mesoporous perovskite solar cells

Abstract Modelling non-planar perovskite solar cells (PSCs) in 1D is very challenging due to strong interfacial and geometric interactions. This affects especially mesoporous, structured tandem, phase segregated and bulk heterojunction solar cells. We present ChargeFabrica, an open-source, two-dimensional electro-ionic drift-diffusion simulation tool designed to address these challenges by simultaneously solving the coupled electronic and ionic transport equations across complex device geometries. Using ChargeFabrica, we successfully replicate experimentally observed thickness-dependent trends in current–voltage ( JV ) curves, the influence of ionic prebiasing and associated EQE, which cannot be fully captured by conventional one-dimensional models. By incorporating realistic device morphologies and experimentally demonstrated defect densities, the simulator accurately predicts performance losses, field inversion effects, and the impact of geometric and interfacial properties. ChargeFabrica thus provides a robust platform for understanding and optimizing the interplay between ion migration and charge collection in mesoporous PSCs and will aid future development of perovskite device architectures.