Unlocking 27.3% Perovskite Solar Cells and Ultra‐Stable Flexible Modules via Multidentate Molecular‐Mediated Buried‐Interface Reconstruction

This study presents a groundbreaking strategy for overcoming critical limitations in inverted perovskite solar cells (PSCs) by introducing multidentate molecular‐mediated buried‐interface reconstruction. Focusing on the persistent challenges of chemical and electronic disorder at the NiO x /self‐assembled monolayer (SAM) interface, we utilize a bisphosphonate molecular mediator to orchestrate a coherent interfacial framework. This strategy simultaneously passivates NiO x defects, regulates SAM assembly, and coordinates with undercoordinated Pb 2+ at the perovskite interface. The resulting multidentate interaction not only homogenizes the interfacial energetics but also suppresses nonradiative recombination, thereby stabilizing carrier dynamics and enhancing device performance. With this approach, we achieve champion‐certified efficiencies of 27.31% for small‐area rigid PSCs, 24.52% for flexible devices, and 17.11% for large‐area flexible modules (684.75 cm 2 ). Remarkably, the engineered interface also demonstrates exceptional durability, with flexible modules retaining over 94% of their initial power output after 3250 h of operation. This work establishes a scalable and versatile paradigm for buried‐interface engineering in PSCs, offering a path toward the development of high‐performance, ultra‐stable flexible photovoltaics with broad application potential.