Perovskite Solar Cells In article number 2000621, Wei Wang, Zongping Shao, and co-workers introduced a gentle butyl acrylate additive into MAPbI3-based perovskite solar cells to enhance the efficiency and stability by improving perovskite film quality, constructing suitable energy level alignment and increasing charge carrier lifetime. Consequently, the device with butyl acrylate additive delivers a high power conversion efficiency of 20.0% and superior moisture/thermal stability under ambient conditions.