• • BDF-1 acceptor achieves a binary power conversion efficiency of 12.2%, demonstrating competitive performance without alkoxy substitution, which reduces synthetic complexity and cost.
• • Ternary blend with PM6 and BTP-eC9 boosts efficiency to 19.5%, indicating excellent compatibility with mainstream donor polymers and potential for high-performance tandem or ternary devices.
• • Density functional theory calculations confirm near-coplanar backbone geometry enabled by furan-thiophene linkages, achieving intrinsic planarity without side-chain conformational locking, which preserves electronic levels for donor compatibility.
• • The design eliminates electronically perturbing alkoxy groups, avoiding undesirable HOMO level elevation, thus maintaining energy level alignment with wide-bandgap donors and enabling efficient charge transfer.