An Interpenetrating Alumina-2D Perovskite Structure for Synergistic Passivation in Carbon-Based Perovskite Solar...

Carbon-based perovskite solar cells (C-PSCs) have attracted extensive attention due to their excellent environmental stability and low cost. 2D perovskite passivation has been widely employed as an effective strategy to enhance device stability in C-PSCs. However, this strategy often fails to simultaneously enhance efficiency and stability, owing to the random crystallization and disordered distribution of the 2D perovskite phase. Herein, phenethylammonium iodide and aluminum oxide (Al₂O₃) are employed to regulate the growth of 2D perovskites, forming an ordered interpenetrating alumina-2D perovskite structure. This unique architecture not only suppresses surface defects in the perovskite but also establishes an energy-level gradient, thereby improving energy-level alignment and facilitating interfacial charge extraction. Consequently, the hole transport layer-free C-PSCs fabricated under ambient air conditions achieved a power conversion efficiency of 18.1% and a T80 stability of 2500 h, demonstrating the effectiveness of the Al₂O₃-2D perovskite structure in enabling highly efficient and stable C-PSCs.