title: Single-Junction Binary-Blend Nonfullerene Polymer Solar Cells with 12.1% Efficiency.
abstract: A new fluorinated nonfullerene acceptor, ITIC-Th1, has been designed and synthesized by introducing fluorine (F) atoms onto the end-capping group 1,1-dicyanomethylene-3-indanone (IC). On the one hand, incorporation of F would improve intramolecular interaction, enhance the push-pull effect between the donor unit indacenodithieno[3,2-b]thiophene and the acceptor unit IC due to electron-withdrawing effect of F, and finally adjust energy levels and reduce bandgap, which is beneficial to light harvesting and enhancing short-circuit current density (JSC). On the other hand, incorporation of F would improve intermolecular interactions through CF···S, CF···H, and CF···π noncovalent interactions and enhance electron mobility, which is beneficial to enhancing JSCand fill factor. Indeed, the results show that fluorinated ITIC-Th1 exhibits redshifted absorption, smaller optical bandgap, and higher electron mobility than the nonfluorinated ITIC-Th. Furthermore, nonfullerene organic solar cells (OSCs) based on fluorinated ITIC-Th1 electron acceptor and a wide-bandgap polymer donor FTAZ based on benzodithiophene and benzotriazole exhibit power conversion efficiency (PCE) as high as 12.1%, significantly higher than that of nonfluorinated ITIC-Th (8.88%). The PCE of 12.1% is the highest in fullerene and nonfullerene-based single-junction binary-blend OSCs. Moreover, the OSCs based on FTAZ:ITIC-Th1 show much better efficiency and better stability than the control devices based on FTAZ:PC71BM (PCE = 5.22%).
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.|Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Fuwen
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.|Fujian Key Laboratory of Polymer Materials, College of Materials Science and Engineering, Fujian Normal University, Fuzhou, 350007, China.
authors.forename: Shuixing
authors.initials: S
authors.lastname: Dai
authors.affiliation: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.
authors.forename: Jiayu
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Fujian Key Laboratory of Polymer Materials, College of Materials Science and Engineering, Fujian Normal University, Fuzhou, 350007, China.
authors.forename: Qidan
authors.initials: Q
authors.lastname: Ling
authors.affiliation: National Center for Nanoscience and Technology, Beijing, 100190, China.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Wei
authors.affiliation: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: You
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Chunru
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhan
keywords: fluorination; fused-ring electron acceptors; nonfullerene; polymer solar cells