In‐Situ Growth 2D MOF Template for Steering Perovskite Crystallization and Interface toward Efficient and Stable Solar Cells

ABSTRACT Perovskite solar cells show great promise in the field of sustainable energy. However, disordered crystallization of perovskite films and interfacial defects remain critical factors restricting the enhancement of device performance and stability. Metal‐organic frameworks (MOFs) materials, featuring flexibly designable porous structures and functional active sites, have been employed to regulate perovskite crystallization kinetics and modify interfacial defects. Nevertheless, conventional deposition strategies often lead to issues like material aggregation and non‐uniform distribution, hindering the construction of an ideal interface and introducing additional recombination centers. To address this critical challenge, this work innovatively proposes the growth of MOFs on the surface of metal oxide electron transport layer (ETL). This constructs a perovskite growth substrate that chemically bonds to the ETL, ensuring excellent conformality. This strategy leverages the ordered pore channels and abundant coordination sites within the MOFs skeleton to induce high‐quality crystallization of the perovskite, effectively reducing interfacial defects and optimizing the energy level alignment of the device. The resulting device shows a power conversion efficiency of 25.81%, combined with good operational stability. This study provides a universal in‐situ MOFs integration scheme, offering a novel interfacial engineering paradigm for crystallization control and advancing MOFs application in efficient, stable photovoltaics.