Recent progress in stabilizing perovskite solar cells through two-dimensional modification

Tremendous progress has been made in lead halide perovskite solar cells (PSCs) with the record power conversion efficiency exceeding 25%. However, poor stability is the most significant obstacle hindering their practical applications. Therefore, improving stability becomes the primary focus of PSC research. Recently, a strategy of modifying the three-dimensional perovskite structures with hydrophobic organic cations for two-dimensional (2D) perovskites has been explored and proven beneficial for both PSC efficiency and stability. Herein, multi-dimensional tuning of the bulk and interfaces of perovskite materials and their influences on device performance and stability are reviewed. In addition, the effects of defect passivation and interface functionalization are discussed. Finally, the mechanisms of stability improvement through 2D modifications are discussed.