A case study of comparing two dimerized acceptor molecules built by different branch-connected and terminal-connected approaches  

作　　者：Kangqiao Ma Huazhe Liang Yuxin Wang Tengfei He Tainan Duan Xiaodong Si Wendi Shi Guankui Long Xiangjian Cao Zhaoyang Yao Xiangjian Wan Chenxi Li Bin Kan Yongsheng Chen 

机构地区：[1]State Key Laboratory and Institute of Elemento-Organic Chemistry,Frontiers Science Center for New Organic Matter,The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials,Institute of Polymer Chemistry,Renewable Energy Conversion and Storage Center(RECAST),College of Chemistry,Nankai University,Tianjin 300071,China [2]School of Materials Science and Engineering,National Institute for Advanced Materials,Renewable Energy Conversion and Storage Center(RECAST),Nankai University,Tianjin 300350,China [3]Chongqing Institute of Green and Intelligent Technology,Chongqing School,University of Chinese Academy of Sciences(UCAS Chongqing),Chinese Academy of Sciences,Chongqing 400015,China

出　　处：《Science China Chemistry》2024年第5期1687-1696,共10页中国科学（化学英文版）

基　　金：supported by the Ministry of Science and Technology of China (National Key R&D Program of China,2022YFB4200400, 2019YFA0705900);the National Natural Science Foundation of China (21935007, 52025033, 22204119),Tianjin City(22JCQNJC00530);Haihe Laboratory of Sustainable Chemical Transformations。

摘　　要：Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencies, especially fill factors(FFs), still need to be improved. This probably originates from unsymmetrical molecular structure/conformation-determined less compact/ordered molecular stackings, such as ineffective stackings of constraint terminals. Herein, an exotic dimerized SMA of BC-Th is established by bridging the branched groups(BC-type, branch coupling) of two monomers rather than conventional terminal units(TC-type, terminal coupling). Benefiting from the three-dimensional conformation and more uncurbed terminals,BC-Th exhibits multiple molecular orientations along with a larger dielectric constant and electron mobility compared with TCTh. Finally, an efficiency of 17.43% is achieved by BC-Th-based OSCs, along with the highest FF of 79.13% among all dimerized SMAs-based OSCs to date. When introducing L8-BO as the third component, overall enhanced efficiency of 18.05%and FF of 80.11% are further afforded. Contrarily, TC-Th-based OSCs exhibit much inferior PCE of 16.29% and FF of 74.81%,demonstrating the great advantages of “branch coupling” over “terminal coupling” when building dimerized SMAs.

关 键 词：organic solar cells dimerized acceptor molecules branch coupling morphology control stability 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TQ317[化学工程—高聚物工业]