Simulation-based insights into light soaking and light-induced degradation in perovskite solar cells

Perovskite solar cells have achieved remarkable power conversion efficiencies, yet their long-term stability remains a critical challenge. Progress in understanding this issue can be supported by combining modelling and characterization of the experimental behaviour obtained during ageing. Degradation studies often rely on post-mortem analysis, which is time-intensive, costly, and requires expertise. Here, we present a modelling framework that provides insights into the underlying mechanisms using simple electrical measurements performed during ageing tests. Drift-diffusion and transfer-matrix simulations of the cell optoelectronic response are combined with a genetic algorithm to reproduce the measured JV characteristics. By tracking the evolution of correlations between electrical parameters (VOC, JSC and FF), simulated mechanisms are compared with experimental data, enabling discrimination between feasible pathways associated with performance improvement during light soaking and light-induced degradation. These mechanisms are simulated by varying material parameters such as charge-carrier mobilities, doping levels, defect concentrations in the absorber and at the perovskite/transport-layer interfaces, and parasitic resistances. Comparison between experiment and simulation distinguishes mechanisms that are consistent with the measured trajectories from those that are not, while highlighting plausible candidates associated with both performance improvement during light soaking and light-induced degradation, thereby providing new insights into perovskite solar cell stability.