Degradation process of perovskite solar cells due to pinholes being transformed into current leakage paths

Abstract The process by which pinholes formed in the perovskite (PVK) layer are transformed into current leakage paths was elucidated through model experiments and simulations. Pinholes were intentionally formed in the PVK layer using laser processing techniques. The effect of the pinholes on the performance of the perovskite solar cells (PSCs) was evaluated. In addition, device simulations show the current density – voltage characteristics and the current distribution in the PSCs with the pinholes. Immediately after the fabrication of pinholes, the pinholes did not act as the current leakage paths. However, 2 weeks of dark storage and 3 min of activation by Air Mass 1.5 Global (AM 1.5 G) irradiation caused some formed-pinholes to transform into the current leakage paths. The device simulations indicate that before the pinhole transforms into the current leakage path, the current is concentrated at the bottom of the pinhole, and this current concentration creates a current leakage path.