Abstract Three donor-acceptor type quinoxaline-based conjugated polymers, in which electron-donating indacenodithiophene (IDT) and indacenodithieno[3,2-b]thiophene (IDTT) were connected to the electron-accepting 2,3-diphenylquinoxaline (DPQ) derivatives, were synthesized using the Stille coupling reaction. To investigate the effects of the strong electron-withdrawing cyano ( CN) substituent on the photovoltaic properties of polymers, it was selectively introduced in the DPQ unit on the polymer backbone. The combination of IDT and the standard DPQ produced the reference polymer IDT-Qx, while the coupling of IDT and IDTT with mono-CN substituted DPQ provided the target polymers IDT-QxCN and IDTT-QxCN, respectively. Owing to the significant contributions of the CN substituent, IDT-QxCN and IDTT-QxCN exhibited better photovoltaic performances than IDT-Qx reference. Furthermore, the presence of more planar two thieno[3,2-b] thiophenes in IDTT than the two thiophenes in IDT allowed IDTT-QxCN to display the highest power conversion efficiency (5.47%) with an open circuit voltage of 0.95 V, short-circuit current density of 15.30 mA cm−2, and fill factor of 56.95%.

中文翻译：

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氰基取代基对喹喔啉基聚合物光伏性能的影响

摘要 三种供体-受体型喹喔啉基共轭聚合物，其中给电子的茚二噻吩（IDT）和茚二噻吩并[3,2-b]噻吩（IDTT）与受电子的2,3-二苯基喹喔啉（DPQ）衍生物相连。 , 是使用 Stille 偶联反应合成的。为了研究强吸电子氰基 (CN) 取代基对聚合物光伏性能的影响，将其选择性地引入聚合物骨架上的 DPQ 单元中。IDT 和标准 DPQ 的组合产生了参考聚合物 IDT-Qx，而 IDT 和 IDTT 与单 CN 取代的 DPQ 的偶联分别提供了目标聚合物 IDT-QxCN 和 IDTT-QxCN。由于 CN 取代基的显着贡献，IDT-QxCN 和 IDTT-QxCN 表现出比 IDT-Qx 参考更好的光伏性能。此外，IDTT 中存在的两个噻吩并 [3,2-b] 噻吩比 IDT 中的两个噻吩更多，这使得 IDTT-QxCN 显示出最高的功率转换效率（5.47%），开路电压为 0.95 V，短路-电路电流密度为 15.30 mA cm-2，填充因子为 56.95%。