Time-Varying Luminescence Imaging for Degradation Diagnosis of Perovskite Photovoltaic Devices

We present degradation diagnosis of perovskite photovoltaic devices using luminescence imaging of operating devices. The photoluminescence images and spatial distribution were found to change under light illumination, indicating that the light-induced changes may be caused by lateral ion migration. The spatial variation in intensity may reflect the local voltage influenced by ion migration. The change in spatial distribution indicates the abundance of mobile defects in the absorber, indicating that there is room for improvement in the quality of perovskite absorber layer. Our findings provide a simple and non-destructive diagnosis of lateral ion-migration-induced change of perovskite solar cells.