Tuning the intermolecular interaction of A_(2)-A_(1)-D-A_(1)-A_(2) type non-fullerene acceptors by substituent engineering for organic solar cells with ultrahigh V_(OC) of ~1.2 V  

作　　者：Xiaochen Wang Ailing Tang Jing Yang Mengzhen Du Jianfeng Li Gongqiang Li Qiang Guo Erjun Zhou 

机构地区：[1]CAS Key Laboratory of Nanosystem and Hierarchical Fabrication,CAS Center for Excellence in Nanoscience,National Center for Nanoscience and Technology,Beijing 100190,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory of Flexible Electronic&Institute of Advanced Materials,Jiangsu National Synergistic Innovation Center for Advanced Materials,Nanjing Tech University,Nanjing 211816,China [4]Henan Institute of Advanced Technology,Zhengzhou University,Zhengzhou 450003,China

出　　处：《Science China Chemistry》2020年第11期1666-1674,共9页中国科学（化学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(51773046,51673048,21602040);the Strategic Priority Research Program of Chinese Academy of Sciences(XDB36000000);the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDBSSW-SLH033);the National Key Research and Development Program of China(2017YFA0206600).

摘　　要：For non-fullerene acceptors(NFAs)with linear A_(2)-A_(1)-D-A_(1)-A_(2) backbone,there are three kinds of possible intermolecular interaction,A_(1)-A_(1),A_(1)-A_(2) and A_(2)-A_(2) stacking.Hence,it is a huge challenge to control this interaction and investigate the effect of intermolecular stacking model on the photovoltaic performance.Here,we adopt a feasible strategy,by utilizing different substituent groups on terminal A2 unit of dicyanomethylene rhodanine(RCN),to modulate this stacking model.According to theoretical calculation results,the molecule BTA3 with ethyl substituent packs via heterogeneous interaction between A_(2) and A_(1) unit in neighboring molecules.Surprisingly,the benzyl group can effectively transform the aggregation of BTA5 into homogeneous packing of A_(2)-A_(2) model,which might be driven by the strong interaction between benzyl and A1(benzotriazole)unit.However,different with benzyl,phenyl end group impedes the intermolecular interaction of BTA4 due to the large steric hindrance.When using a BTA-based D-π-A polymer J52-F as donor according to“Same-A-Strategy”,BTA3-5 could achieve ultrahigh open-circuit voltage(VOC)of 1.17–1.21 V.Finally,BTA5 with benzyl groups realized an improved power conversion efficiency(PCE)of 11.27%,obviously higher than that of BTA3(PCE=9.04%)and BTA4(PCE=5.61%).It is also worth noting that the same trend can be found when using other four classic p-type polymers of P3HT,PTB7,PTB7-Th and PBDB-T.This work not only investigates the intermolecular interaction of A_(2)-A_(1)-D-A_(1)-A_(2) type NFAs for the first time,but also provides a straightforward and universal method to change the interaction model and improve the photovoltaic performance.

关 键 词：BENZOTRIAZOLE dicyanomethylene rhodanine end group engineering intermolecular interaction non-fullerene acceptor 

分 类 号：TM914.4[电气工程—电力电子与电力传动]