Impact of Ionic Conduction on Hysteresis and Long-Term Degradation in Perovskite Solar Cells

Perovskite solar cells, known for their high efficiency, face a challenge with hysteresis in current–voltage (J–V) measurements, complicating accurate characterization. This study explores the factors contributing to hysteresis, with a particular focus on ionic conduction, to address this issue. We have developed an analytical model incorporating transient response analysis to reproduce hysteresis and evaluate the impact of ionic parameters such as mobility and interfacial recombination. Our findings identified iodine vacancy (VI) conduction as a primary cause of J–V hysteresis, offering significant insights for the field. We also discovered that methylammonium vacancies (VMA) contributed to long-term cell performance degradation, with diffusion coefficients higher than previously reported. This research highlights the practical importance of understanding ionic conduction to improve the characterization and efficiency of perovskite solar cells, emphasizing the need for further investigation in this area.