A Self‐Assembled 3D/0D Quasi‐Core–Shell Structure as Internal Encapsulation Layer for Stable and Efficient FAPbI<sub>3</sub> Perovskite Solar Cells and Modules
Yuqi Wang, Chao Yang, Zhen Wang, Gu Li, Zhengchi Yang, Xinyang Wen, Xiaowen Hu, Yue Jiang, Shien‐Ping Feng, Yiwang Chen, Guofu Zhou, Jun‐Ming Liu, Jinwei Gao
Abstract
Abstract FAPbI 3 perovskites have garnered considerable interest owing to their outstanding thermal stability, along with near‐theoretical bandgap and efficiency. However, their inherent phase instability presents a substantial challenge to the long‐term stability of devices. Herein, this issue through a dual‐strategy of self‐assembly 3D/0D quasi‐core–shell structure is tackled as an internal encapsulation layer, and in situ introduction of excess PbI 2 for surface and grain boundary defects passivating, therefore preventing moisture intrusion into FAPbI 3 perovskite films. By utilizing this method alone, not only enhances the stability of the FAPbI 3 film but also effectively passivates defects and minimizes non‐radiative recombination, ultimately yielding a champion device efficiency of 23.23%. Furthermore, the devices own better moisture resistance, exhibiting a T 80 lifetime exceeding 3500 h at 40% relative humidity (RH). Meanwhile, a 19.51% PCE of mini‐module (5 × 5 cm 2 ) is demonstrated. This research offers valuable insights and directions for the advancement of stable and highly efficient FAPbI 3 perovskite solar cells.