Advanced Energy Materials
Perovskite Solar Cells: Reverse‐Graded 2D Ruddlesden–Popper Perovskites for Efficient Air‐Stable Solar Cells
Yi Wei, Huailong Chu, Yuyang Tian, Baoquan Chen, Kaifeng Wu, Junhui Wang, Xichuan Yang, Bin Cai, Yongfei Zhang, Jijun Zhao
In article number 1900612, Jijun Zhao and co‐workers report new 2D Ruddlesden‐Popper Perovskites (RPPs) for solar cells. The films exhibit reverse‐graded quantum‐well distribution, which facilitates internal charge transfer and photon collection. This structure enables vulnerable large‐n RPPs to be protected by more resistant small‐n RPPs. Thus, a high‐performance solar cell with 15.05% efficiency is achieved and the stability in humid conditions is significantly enhanced.