Interface passivation strategies for high-performance perovskite solar cells using two-dimensional perovskites

The performance of perovskite solar cells (PSCs) is critically influenced by the quality of interfaces, including grain boundaries and perovskite surfaces. These interfaces are often highly defective, leading to non-radiative recombination and impaired charge transfer. Additionally, operational conditions can induce undesirable chemical reactions, affecting long-term stability. This review summarizes advancements over the past five years in achieving high-efficiency (near or above 25%) through interface passivation. Notably, using two-dimensional/three-dimensional (2D/3D) hybrid perovskites, which combine the stability of 2D perovskites with the efficiency of 3D perovskites, has emerged as a promising strategy. We reviewed recent progress in interface passivation strategies, focusing on the implementation of 2D/3D perovskite passivation across buried interfaces, grain boundaries and top interfaces. Finally, we discussed challenges and future directions for multi-interface cooperative passivation, charge dynamics and degradation mechanisms.