Formamidinium (FA)-based perovskite solar cells (PSCs) have emerged as one of the most promising candidates for next-generation photovoltaics due to their exceptional power conversion efficiency (PCE). However, their commercial deployment is hindered by poor stability, particularly under strict environmental stresses like high temperature, with interface degradation and ion migration being key challenges. In this work, we introduce metal–organic framework (MOF) materials composed of assembled Zr clusters and functional amino/sulfhydryl groups at the SnO₂/perovskite interface within the n–i–p structure to address these issues. The incorporation of MOFs—specifically their robust framework with confined spatial structure and functional groups—plays a pivotal role in hindering oxygen migration from SnO₂ to perovskite, leading to enhanced thermal stability of both perovskite films and PSCs. Furthermore, the anchoring of MOF on SnO₂ and perovskite is essential for passivating interface defects, promoting perovskite crystallization, and reducing carrier recombination, all of which contribute to enhanced charge transport. As a result, the MOF-modified devices achieve a champion PCE of 25.22%, with the MOF-modified devices retaining 100% of their initial PCE after 2000 h of thermal aging at 85 °C in N₂. This study highlights the structural integrity and functionality of MOFs for achieving high-performance and long-term stable PSCs.

Perovskite solar cells (PSCs) have seen remarkable progress in recent years, largely attributed to various additives that enhance both efficiency and stability. Among these, fluorine-containing additives have garnered significant interest because of their unique hydrophobic properties, effective defect passivation, and regulation capability on the crystallization process. However, a targeted structural approach to design such additives is necessary to further enhance the performance of PSCs. Here, fluoroalkyl ethylene with different fluoroalkyl chain lengths (CH₂CH(CF₂)_nCF₃, n = 3, 5, and 7) as liquid additives is used to investigate influences of fluoroalkyl chain lengths on crystallization regulation and defect passivation. The findings indicate that optimizing the quantity of F groups plays a crucial role in regulating the electron cloud distribution within the additive molecules. This optimization fosters strong hydrogen bonds and coordination effects with FA⁺ and uncoordinated Pb²⁺, ultimately enhancing crystal quality and device performance. Notably, 1H,1H,2H-perfluoro-1-hexene (PF₃) with the optimal number of F presents the most effective modulation effect. A PSC utilizing PF₃ achieves an efficiency of 24.05%, and exhibits exceptional stability against humidity and thermal fluctuations. This work sheds light on the importance of tailored structure designs in additives for achieving high-performance PSCs.