Analysis and Modelling of Recovery and Degradation Mechanisms in Perovskite Solar Cells

Perovskite solar cells have reached outstanding results in terms of power conversion efficiency over the last years. However, their stability remains a challenge. Post-degradation studies can be found in the literature, but limited research on the dynamics of recovery and degradation has been conducted. Modelling of experimental behavior provides new insights into the understanding these mechanisms in perovskite solar cells. Drift-diffusion and transfer-matrix methods are employed to simulate optoelectrical characteristics, and the initial performances of solar cells are reproduced by means of a genetic algorithm. The evolution of the correlation among optoelectrical parameters is employed to assess the resemblance of experimental data and simulated mechanisms. This allows to propose feasible mechanisms relevant for recovery and degradation. Simulated mechanisms are computed by varying material parameters such as charge carrier mobility, doping and defect concentration in the absorber and transport layers, as well as in their interfaces. Relevant mechanisms to understand the experimental behavior are proposed, while allowing to discard the unlikely ones. This provides new insights into recovery and degradation of perovskite solar cells and serves already to identify the possible reversibility of such mechanisms, enabling to focus experimental efforts on mitigating irreversible degradation.