Alkoxy‐Substituted Anthrabis(Thiadiazole)‐Terthiophene Copolymers for Organic Photovoltaics: A Unique Wavy Backbone Enhances Aggregation, Molecular Order, and Device Efficiency

Two polymer donors, PATz3T-o6BO and PATz3T-o6HD, incorporating alkoxy-substituted anthra[1,2-c:5,6-c′]bis([1,2,5]thiadiazole), were strategically designed and synthesized. The unique wavy backbone of these polymers effectively reduced aggregation, leading to enhanced solubility and significantly improved molecular ordering. Consequently, the PATz3T-o6HD:Y12-based solar cells achieved a power conversion efficiency (PCE) of 7.94%. These findings provide valuable insights into the molecular design of high-performance polymer donors for organic photovoltaics (OPVs).