Near-Infrared Double-Cable Conjugated Polymers with Tunable Phenyl-Alkyl Linkers for High-Performance Organic Solar Cells

Y-series acceptors with near-infrared absorption have been employed as side units for constructing double-cable conjugated polymers due to their outstanding properties. In this work, a class of Y-acceptor-based double-cable polymers utilizing phenyl-alkyl chains as linkers were developed. By varying the number of phenyl units from one to three, three double-cable conjugated polymers, named LP01, LP02, and LP03, were synthesized. When the three polymers were applied to single-component organic solar cells (SCOSCs), the devices based on LP01, LP02, and LP03 showed power conversion efficiencies (PCE) of 11.18%, 9.26%, and 11.33%, respectively. Further studies revealed that LP01 and LP03 exhibited tighter molecular packing and improved charge transport, resulting in better efficiencies. Crucially, all devices demonstrated superior thermal stability by maintaining over 90% of their initial efficiency after continuous heating at 80 °C for 1000 h. Furthermore, when LP03 was incorporated into a D18:L8-BO binary system, the ternary OSCs achieved a PCE of 19.68% with improved thermal stability.