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

作　　者：Jianchao Jia Nannan Zheng Zhenfeng Wang Yunping Huang Chunhui Duan Fei Huang Yong Cao 

机构地区：[1]Institute of Polymer Optoelectronic Materials and Devices,State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510640,China

出　　处：《Science China Chemistry》2017年第11期1458-1467,共10页中国科学（化学英文版）

基　　金：supported by the Ministry of Science and Technology(2014CB643501);the National Natural Science Foundation of China(21520102006,21634004,21490573);the Guangdong Natural Science Foundation(S2012030006232)

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.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.

关 键 词：organic solar cells BULK-HETEROJUNCTION non-fullerene acceptors end-capping groups 

分 类 号：TM914.4[电气工程—电力电子与电力传动]