Enhancement of the Ultraviolet Stability of Perovskite Solar by the Interface Modified with Cesium Chloride

Stability is an important factor affecting the application of perovskite solar cells (PSCs). The decomposition of perovskite materials induced by ultraviolet (UV) light is one of the reasons influencing the stability. Herein, a simple method for enhancing the stability of n– i –p PSCs by using CsCl to modify the interface between the electron transport layer and the perovskite. The results show that the introduction of CsCl to modify the interface is conducive to the growth of perovskite films and inhibits the interface recombination, which effectively improves the efficiency and stability of PSCs. Compared with the control PSCs, the champion target PSCs showed higher power conversion efficiency (from 21.21% to 23.73%). In addition, the UV light stability is also improved by about four times. This work emphasizes the importance of CsCl modified interface, and provides an effective way to achieve efficient and stable PSCs at the same time.