Simultaneously Enhancing Efficiency and Stability of Perovskite Solar Cells Through Crystal Cross‐Linking Using Fluorophenylboronic Acid

Abstract Organic‐inorganic metal halide perovskites are regarded as one of the most promising candidates in the photovoltaic field, but simultaneous realization of high efficiency and long‐term stability is still challenging. Here, a one‐step solution‐processing strategy is demonstrated for preparing efficient and stable inverted methylammonium lead iodide (MAPbI 3 ) perovskite solar cells (PSCs) by incorporating a series of organic molecule dopants of fluorophenylboronic acids (F‐PBAs) into perovskite films. Studies have shown that the F‐PBA dopant acts as a cross‐linker between neighboring perovskite grains through hydrogen bonds and coordination bonds between F‐PBA and perovskite structures, yielding high‐quality perovskite crystalline films with both improved crystallinity and reduced defect densities. Benefiting from the repaired grain boundaries of MAPbI 3 with the organic cross‐linker, the inverted PSCs exhibit a remarkably enhanced performance from 16.4% to approximately 20%. Meanwhile, the F‐PBA doped devices exhibit enhanced moisture/thermal/light stability, and specially retain 80% of their initial power conversion efficiencies after more than two weeks under AM 1.5G one‐sun illumination. This work highlights the impressive advantages of the perovskite crystal cross‐linking strategy using organic molecules with strong intermolecular interactions, providing an efficient route to prepare high‐performance and stable planar PSCs.