Efficient small-molecule donor with improved structural order and molecular aggregation enabled by side-chain modification

作     者：Haiyan Chen Ke Yang Peihao Huang Dingqin Hu Hua Tang Jie Lv Gang Li Shirong Lu 

作者机构：Chongqing Institute of Green and Intelligent TechnologyChongqing SchoolUniversity of Chinese Academy of Sciences(UCAS Chongqing)Chinese Academy of SciencesChongqing400714PR China Chongqing UniversityChongqing400044PR China Department of Electronic and Information EngineeringThe Hong Kong Polytechnic UniversityHong Kong SARPR China 

出 版 物：《Materials Reports(Energy)》 (材料导报（能源）（英文）)

年 卷 期：2021年第1卷第4期

页      面：54-60页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：the Natural Science Foundation of Chongqing(cstc2019jcyj-msxmX0400) Youth Innovation Promotion Association Chinese Academy of Sciences(2020379) Chongqing Funds for Distinguished Young Scientists(cstc2020jcyj-jqX0018) General Program of National Natural Science Foundation of China(62074149) National Natural Science Foundation of China(51961165102) 

主　　题：Organic solar cell Small-molecule donor Side-chain modification Molecular dipole moment Morphology 

摘      要：Side-chain modification is a proven effective approach for morphology manipulation in organic solar cells(OSCs).However,in-depth analysis and investigation involving side-chain modification towards morphology improvement,including molecular microstructure,orientating packing and aggregation are urgent for all-small-molecule(ASM)***,employing a fluorine-modified two-dimension benzodithiophene(BDT)as central unit,we contrastively synthesized two small-molecule donors,namely BDT-F-SR and BDT-F-R,each welding alkylthio side-chains on thienyl of central BDT unit and the other grafted non-sulfuric alkyl *** predicted,the synergetic side-chain modification of fluorination and alkyl changeover triggers diverse molecular dipole moments and orientations,resulting in different molecular energy levels,thermal stabilities,molecular planarity and ***,together with the preeminent small-molecule acceptor Y6,BDT-F-R-based ASM OSCs obtain enhanced power conversion efficiency(PCE)of 13.88%compared to BDT-F-SR-based devices(PCE of 12.75%)with more suitable phase-separation and balanced carrier *** contrast results reveal that alkyl sidechains seem to be a more satisfactory partner for fluorine-modified 2D BDT-based small-molecule donors compared to alkylthio pendants,and highlight the significance of subtle side-chain modification for molecular structural order fun-tuning and morphology control,laying the foundation for efficient ASM OSCs.