Constructing Stable Heterointerface with Self‐Assembled Molecular Bridge for Efficient and Durable Perovskite Solar Cells

ABSTRACT The interfacial carrier loss and unstable buried heterointerface are significant factors that limit the performance and stability of n‐i‐p perovskite solar cells. In this work, a molecular bridge constructed with natural pyridoxal phosphate (PLP) self‐assembled molecules is first developed to facilitate the transport of charge carriers and strengthen the SnO ₂ /perovskite buried heterointerface. The PLP molecules with phosphonic acid groups anchored on the surface of SnO ₂ film, thereby passivating interfacial defects and adjusting the energy level of SnO ₂ film. Furthermore, the PLP molecular bridge regulates the crystallization kinetics of perovskite through multiple bonding mechanisms, thereby releasing residual stress and promoting the growth of high‐quality perovskite films. Ultimately, the optimized devices achieve the highest power conversion efficiency of 25.49% with low open‐circuit voltage loss of 0.33 V due to the efficient carrier transport at the SnO ₂ /perovskite buried heterointerface. More importantly, the encapsulated device maintains 91.64% of its initial efficiency under a thermal cycling test (−40°C to 85°C; 300 cycles) and 91.87% under maximum power point tracking (65°C; 1000 h) due to the strengthened heterointerface. This work demonstrates an effective way to fabricate efficient and durable PSCs via reducing carrier loss and strengthening the SnO ₂ /perovskite buried heterointerface with self‐assembled molecular bridge.