The Effect of Redox Reactions on the Stability of Perovskite Solar Cells

Organic-inorganic hybrid perovskites have attracted tremendous attention in the photovoltaic industry because of their low cost, simple production process, and high efficiency. However, (photo)stability is still one of the main problems that limits their development and enormous efforts have been made in this area. In this Review, we focus on the ubiquitous redox reactions in perovskite solar cells (PSCs), reveal the reasons behind the occurrence of the reactions (both external and internal factors) and the resulting effects (favorable and unfavorable), and collect methods to mitigate or block the occurrence of the reaction. Then, we summarize the means of characterizing redox reactions to visualize their presence and mechanisms. Finally, we envision future research directions in this field and consider redox reactions a double-edged sword. We hope that these insights will contribute to accelerating the commercialization of PSCs.