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Designing functional fullerenes with roles beyond defect passivation and electron‐transporting for perovskite solar cells (PSCs) is essential to the development of fullerenes and PSCs. Here, the authors design and synthesize a functional fullerene, FPD, composed of a C60 cage, a porphyrin ring, and three pentafluorophenyl groups. The structure features of FPD enable it can form chemical interactions with the perovskite lattices. These interactions enhance the defect passivation effect and prevent the decomposition of perovskite under irradiation. As a result, the FPD‐based device yields an improved power conversion efficiency of 23% with substantially enhanced operational stability (T80 > 1500 h). Furthermore, once got damaged, the FPD can prevent lead leakage by forming a stable and water‐insoluble complex (FPD‐Pb). Their findings provide a novel strategy to achieve high‐performance and eco‐friendly PSCs with functional fullerene materials. [ABSTRACT FROM AUTHOR]

Improving the efficiency of tin-based perovskite solar cells (TPSCs) is significantly hindered by energy level mismatch and weak interactions at the interface between the tin-based perovskite and fullerene-based electron transport layers (ETLs). In this study, four well-defined multidentate fullerene molecules with 3, 4, 5, and 6 diethylmalonate groups, labeled as FM3, FM4, FM5, and FM6 are synthesized, and employed as interfacial layers in TPSCs. It is observed that increasing the number of functional groups in these fullerenes leads to shallower lowest unoccupied molecular orbital (LUMO) energy levels and enhance interfacial chemical interactions. Notably, FM5 exhibits a suitable energy level and robust interaction with the perovskite, effectively enhancing electron extraction and defect passivation. Additionally, the unique molecular structure of FM5 allows the exposed carbon cage to be tightly stacked with the upper fullerene cage after interaction with the perovskite, facilitating efficient charge transfer and protecting the perovskite from moisture and oxygen damage. As a result, the FM5-based device achieves a champion efficiency of 15.05%, significantly surpassing that of the PCBM-based (11.77%), FM3-based (13.54%), FM4-based (14.34%), and FM6-based (13.75%) devices. Moreover, the FM5-based unencapsulated device exhibits excellent stability, maintaining over 90% of its initial efficiency even after 300 h of air exposure., (© 2024 Wiley‐VCH GmbH.)