Rationally utilizing and developing synthetic units is of particular significance for the design of high-performance non-fullerene small-molecule acceptors(SMAs).Here,a thieno[3,2-b]pyrrole synthetic unit was employed to develop a set of SMAs(ThPyl,ThPy2,ThPy3 and ThPy4)by changing the number or the position of the pyrrole ring in the central core based on a standard SMA of IT-4C1,compared to which the four thieno[3,2-b]pyrrole-based acceptors exhibit bathochromic absorption and upshifted frontier orbital energy level due to the strong electron-donating ability of pyrrole.As a result,the polymer solar cells(PSCs)of the four thieno[3,2-b]pyrrole-based acceptors yield higher open-circuit voltage and lower energy loss relative to those of the IT-4Cl-based device.What is more,the ThPy3-based device achieves a power conversion efficiency(PCE)(15.3％)and an outstanding fill factor(FF)(0.771)that are superior to the IT-4Cl-based device(PCE=12.6％,FF=0.758).The ThPy4-based device realizes the lowest energy loss and the smallest optical band gap,and the ternary PSC device based on PM6:BTP-eC9:ThPy4 exhibits a PCE of 18.43％and a FF of0.802.Overall,this work sheds light on the great potential of thieno[3,2-b]pyrrole-based SMAs in realizing low energy loss and high PCE.

Zhenghui Luo;Ruijie Mao;Jianwei Yu;Heng Liu;Tao Liu;Fan Ni;Jiahao Hu;Yang Zou;Anping Zeng;Chun-Jen Su;U-Ser Jeng;Xinhui Lu;Feng Gao;Chuluo Yang;He Yan

Shenzhen Key Laboratory of Polymer Science and Technology,College of Materials Science and Engineering,Shenzhen University,Shenzhen 518060,China;Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration&Reconstruction,Hong Kong University of Science and Technology(HKUST),Hong Kong,China;Hong Kong University of Science and Technology-Shenzhen Research Institute,Shenzhen 518057,China;Department of Physics,Chemistry and Biology(IFM),Link?ping University,Link?ping SE-58183,Sweden;Department of Physics,Chinese University of Hong Kong,Hong Kong,China;Synchrotron Radiation Research Center,Hsinchu Science Park,Hsinchu 30076,China;Department of Chemical Engineering,Tsing Hua University,Hsinchu 30013,China;Hong Kong University of Science and Technology(HKUST)Light-Emitting Diode and Flat Panel Display Technology Research&Development Center,Foshan 526040,China;Hong Kong University of Science and Technology(HKUST)Foshan Research Institute for Smart Manufacturing,Hong Kong,China

国家科学评论（英文版）

[1]Zhenghui Luo;Ruijie Mao;Jianwei Yu;Heng Liu;Tao Liu;Fan Ni;Jiahao Hu;Yang Zou;Anping Zeng;Chun-Jen Su;U-Ser Jeng;Xinhui Lu;Feng Gao;Chuluo Yang;He Yan-.Heteroheptacene-based acceptors with thieno[3,2-b]pyrrrole yield high-performance polymer solar cells)[J].国家科学评论（英文版）,2022(07):99-108

Heteroheptacene,pyrrrole,ThPyl,ThPy2,ThPy3,ThPy4,4C1,bathochromic,of0

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