The effect of current density-voltage measurement conditions on the operational stability of hybrid perovskite solar cells

Organic-inorganic lead halide perovskites have attracted great attention for use in solar cells, because of their efficient solar power conversion, along with compatibility with simple solution processing. To evaluate the operational stability of perovskite solar cells (PSCs), measurements on their current density-voltage (J-V) curves are periodically repeated in most literature studies. However, how the periodic J-V measurements affect the operational stability of PSCs has not been well understood to date. In this study, we found that repeating the J-V measurements, especially applying a voltage higher than the open-circuit voltage of PSCs, under continuous illumination, causes serious ion migration, which lowers the operational stability of PSCs. On the other hand, we observed no decrease in operational stability when the applied voltage is close to or lower than the open-circuit voltage of PSCs during the periodic J-V measurements because of the suppressed ion migration. These findings are important in evaluating the intrinsic operational stability of PSCs.