Synergistic Molecular Engineering of Fully Non‐fused Ring Acceptors for Achieving Efficient Zigzag Charge Transport Channel and Low Non‐Radiative Voltage Loss

Abstract Fully non‐fused ring acceptor (FNFRA) are potentially important for boosting the performance and lowering the material costs of organic solar cells (OSCs). Despite their potential, FNFRA‐based OSCs have not yet matched the performance of their fused ring and partial non‐fused ring counterparts due to limited molecular engineering research. In this work, by incorporating a synergistic strategy of tailoring the β ‐side chain and end‐group of FNFRA with the cyclic “belt” simultaneously, a FNFRA named C6FT‐2F2Cl is constructed. Compared with other symmetric FNFRAs, C6FT‐2F2Cl features a shorter π–π stacking distance and an efficient zigzag charge transport channel, leading to enhanced and balanced charge carrier mobilities, lower non‐radiative energy loss and a higher short‐circuit current density. The power conversion efficiency (PCE) of the C6FT‐2F2Cl‐based OSC reached 13.19%, which is among the best in FNFRA‐based devices. This work provides new valuable insights for the charge transport mechanism associated FNFRAs and paves a new route to the materials design toward high‐performance and low‐cost OSCs.