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

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.

Automated summary

This study demonstrates a one-step solution-processing strategy for preparing efficient and stable inverted methylammonium lead iodide perovskite solar cells (PSCs) by incorporating organic molecule dopants of fluorophenylboronic acids (F-PBAs) into perovskite films. The F-PBA dopant acts as a cross-linker between perovskite grains, improving crystallinity and reducing defect densities. The inverted PSCs with F-PBA dopants exhibit significantly enhanced performance and improved stability under different environmental conditions.