Is light a source of degradation in perovskite solar cells?

Perovskite solar cells have attracted much attention as next-generation solar cells, and many studies are being conducted. However, one of the biggest issues in the perovskite solar cell is low stability or reliability. Several experiments have suggested that light is a source of degradation in perovskite solar cells, but the detail mechanism is yet to be understood. In this study, the light-induced degradation mechanism was analyzed based on the first-principles calculations. We found that the light-induced degradation of organic A-site molecules, which has been proposed in the previous experiments, is difficult to be occured. It was also found that light had little effect on the denaturation of perovskite materials. Through these results, a new degradation process of perovskite materials was proposed, and previous experiments were interpretated based on the process.