The Multiple Roles of Nonfullerene Acceptors in Advancing Perovskite Solar Cells

Perovskite solar cells (PSCs) have now achieved power conversion efficiencies exceeding 27%, benefiting from rapid advancements in device processing and materials. However, challenges in processability and stability remain key barriers to their commercialization. Nonfullerene acceptors (NFAs) have garnered significant attention in perovskite research due to their high electron mobility, hydrophobicity, multiple defect-passivating functional groups, and complementary absorption in the near-infrared region. This review systematically summarizes the roles of NFAs in PSCs as electron transport layers, bulk-heterojunction layers, and interface layers. Finally, design principles are proposed for future NFA materials tailored for highly efficient and stable PSCs, paving the way for the commercialization of PSCs.