The effect of end-capping groups in A-D-A type non-fullerene acceptors on device performance of organic solar cells

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2017,（11）
• 页码范围: 1458-1467
• 页数: 10页
• 语种: 英文
• DOI: 10.1007/s11426-017-9102-1

摘要

A series of novel wide bandgap small molecules (IFT-ECA,IFT-M,IFT-TH and IFT-IC) based on the A-D-A structure with indenofluorene core,thiophene bridge,and different electron-deficient end-capping groups,were synthesized and used as non-fullerene acceptors in organic solar cells.The influences of end-capping groups on the device performance were studied.The four materials exhibited different physical and chemical properties due to the variation of end-capping groups,which further affect the exciton dissociation,charge transport,morphology of the bulk-heterojunction films and device performance.Among them,IFT-IC-based device delivered the best power conversion efficiency of 7.16％ due to proper nano-scale phase separation morphology and high electron mobility,while the devices based on the other acceptors achieved lower device performance (4.14％ for IFT-TH,＜ 1％ for IFT-ECA and IFT-M).Our results indicate the importance of choosing suitable electron-withdrawing groups to construct high-performance non-fullerene acceptors based on A-D-A motif.