摘要: The incorporation of a third component to ternary organic solar cells (T-OSCs) is an effective strategy for enhancing the power conversion efficiency (PCE). While the fluorination extent of acceptor molecules is critical for modulating energy levels, molecular packing, and blend compatibility, systematic studies on the fluorination pattern remain scarce. In this work, we synthesized three novel fluorinated acceptors (o-2F, p-2F, and t-4F) with varied fluorine substitution patterns on the central benzene core via an atom-economical direct C–H arylation route. The influence of the fluorine substitution motif on molecular conformation, aggregation behavior, and device performance was systematically investigated. Theoretical calculations revealed that increased fluorination significantly enhances molecular planarity. Device performance tests demonstrated that the ortho-difluorinated acceptor o-2F promotes favorable nanoscale phase separation and facilitates efficient charge transport. Consequently, the PM6:Y6:o-2F-based TOSCs achieved a notable improvement in PCE from 16.16% to 17.41% compared to the PM6:Y6 binary counterpart, accompanied by concurrent enhancements in open-circuit voltage (from 0.83 V to 0.85 V), short-circuit current (from 26.45 to 27.19 mA cm-2), and fill factor (from 73.56% to 75.33%). In contrast, the excessively fluorinated t-4F led to overly enhanced crystallinity, resulting in limited morphological optimization and marginal PCE improvement. This study underscores the importance of balancing molecular planarity and aggregation through rational fluorination design, providing valuable guidance for developing high-performance acceptor materials for T-OSCs.