Halogen‐Functional Molecules for Synergistic Multi‐Defect Healing in High‐Performance Perovskite Solar Cells

Defect complexity and dynamic coupling in perovskites limit single-target passivation and often incur lattice damage when highly reactive agents are used. Here, we introduce two additives, perfluoropinacol (PFP) and 2,6-dichlorobenzyl chloride (DCB), to achieve synergistic, multiple defect passivation while promoting controlled crystallization. With multiple functional sites targeting distinct defect species (such as VI vacancy, VPb vacancy, PbI antisite, and so on), PFP and DCB act synergistically to achieve comprehensive, integrated defect passivation. The combined action improves defect passivation, delivering high-performance devices: champion PCEs of 25.47% (n-i-p) and 26.47% (p-i-n). Unencapsulated devices exhibit durable stability, retaining 95% of initial efficiency after 1300 h at 65°C and 94% after 1000 h under 1-sun maximum power point tracking (MPPT). This cooperative strategy provides a practical pathway to simultaneously regulate crystallization and suppress deep/shallow defects, advancing efficient and stable perovskite photovoltaics toward industrial deployment.