Peculiarities of perovskite photovoltaics degradation and how to account for them in stability studies

Degradation of perovskite solar cells is shown to be partly reversible in the dark, which significantly affects the lifetime of the cell under operational conditions. In this contribution, complex interplay between reversible and irreversible degradation is discussed on the basis of indoor illumination-recovery experiments and outdoor exposure to natural diurnal cycle. We demonstrate that both photodegradation and subsequent recovery processes are strongly affected by the electrical bias condition during the aging. Light-induced ion migration and metastable traps formation with different dominance under different biases and at different degradation stages might explain observed features.