TY - JOUR
T1 - Effect of Terminal Electron-Withdrawing Group on the Photovoltaic Performance of Asymmetric Fused-Ring Electron Acceptors
AU - Li, Chao
AU - Lu, Guangkai
AU - Ryu, Hwa Sook
AU - Sun, Xiaobo
AU - Woo, Han Young
AU - Sun, Yanming
N1 - Funding Information:
This work was financially supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 21975012, 51825301, and 21734001). H.Y.W. acknowledges the financial support by the National Research Foundation of Korea (2019R1A6A1A11044070, 2020M3H4A3081814).
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/9/28
Y1 - 2022/9/28
N2 - The terminal electron-withdrawing group is thought to strongly influence π-πstacking interactions and thereby the charge transport properties of fused-ring electron acceptors (FREAs). In this work, we designed and synthesized three asymmetric/symmetric small molecule FREAs (LC301, LC302, and LC303), in which three electron-withdrawing functional groups with different polarities (phenyl-fused indanone < thienyl-fused indanone < F-modified phenyl-fused indanone) were selected as the terminal groups. Photophysical properties, electrochemistry, charge transport, and crystalline properties of the materials were studied to investigate the effect of electron-withdrawing abilities of the terminal groups on the properties of FREAs. Starting from the symmetric LC302 (two thienyl-fused indanone terminal groups), we have found that by simply replacing only one thienyl-fused indanone terminal group in symmetric LC302 with one difluorinated phenyl-fused indanone terminal group, the asymmetric LC301-based organic solar cells (OSCs) can yield a high power conversion efficiency (PCE) of 17.21% and a promising fill factor (FF) of 78.1%, which are higher than those of symmetric LC302-based OSCs (PCE = 15.18%, FF = 73.3%) and the asymmetric LC303-based OSCs bearing one thienyl-fused indanone terminal group and one nonfluorinated phenyl-fused indanone terminal group (PCE = 14.28%, FF = 70.3%). The results indicate that the rational selection of terminal groups with different electron-withdrawing capabilities is highly desirable for designing high-performance asymmetric FREAs.
AB - The terminal electron-withdrawing group is thought to strongly influence π-πstacking interactions and thereby the charge transport properties of fused-ring electron acceptors (FREAs). In this work, we designed and synthesized three asymmetric/symmetric small molecule FREAs (LC301, LC302, and LC303), in which three electron-withdrawing functional groups with different polarities (phenyl-fused indanone < thienyl-fused indanone < F-modified phenyl-fused indanone) were selected as the terminal groups. Photophysical properties, electrochemistry, charge transport, and crystalline properties of the materials were studied to investigate the effect of electron-withdrawing abilities of the terminal groups on the properties of FREAs. Starting from the symmetric LC302 (two thienyl-fused indanone terminal groups), we have found that by simply replacing only one thienyl-fused indanone terminal group in symmetric LC302 with one difluorinated phenyl-fused indanone terminal group, the asymmetric LC301-based organic solar cells (OSCs) can yield a high power conversion efficiency (PCE) of 17.21% and a promising fill factor (FF) of 78.1%, which are higher than those of symmetric LC302-based OSCs (PCE = 15.18%, FF = 73.3%) and the asymmetric LC303-based OSCs bearing one thienyl-fused indanone terminal group and one nonfluorinated phenyl-fused indanone terminal group (PCE = 14.28%, FF = 70.3%). The results indicate that the rational selection of terminal groups with different electron-withdrawing capabilities is highly desirable for designing high-performance asymmetric FREAs.
KW - asymmetric small molecule
KW - electron-withdrawing group
KW - fused-ring electron acceptor
KW - organic solar cells
KW - terminal group
UR - http://www.scopus.com/inward/record.url?scp=85138627137&partnerID=8YFLogxK
U2 - 10.1021/acsami.2c10557
DO - 10.1021/acsami.2c10557
M3 - Article
C2 - 36099472
AN - SCOPUS:85138627137
SN - 1944-8244
VL - 14
SP - 43207
EP - 43214
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 38
ER -