AbstractPolythiophenes are the most appealing donor materials in organic solar cells (OSCs) due to their simple chemical structures. However, the topâperformance polythiophenes are typically synthesized via Stille polycondensation, which is problematic due to significant toxicity and poor atom economy. By contrast, direct arylation polycondensation (DArP) is an ecoâfriendly, and atomâefficient alternative for synthesizing conjugated polymers, while the best efficiency for DArPâderived polythiophenes is below 12%. This study reports a series of polythiopheneâbased donors synthesized via DArP. Among these, PT4FâTh reaches a power conversion efficiency (PCE) of 16.4%, which not only matches the current record for polythiopheneâbased donor materials, but also marks the highest PCE achieved by DArPâderived donors to date. The superior performance of PT4FâTh is largely attributed to its optimal temperatureâdependent aggregation behavior and moderate miscibility with acceptors, along with the highest crystallinity among the candidates, resulting in the most favorable blend film morphology. This study underscores the significant potential of DArPâderived polythiophenes in developing highâperformance and ecoâfriendly OSCs.