TY - JOUR
T1 - Asymmetrically Alkyl-Substituted Wide-Bandgap Nonfullerene Acceptor for Organic Solar Cells
AU - Xia, Tian
AU - Li, Chao
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. 21734001, 51825301, and 21674007). H.Y.W. is grateful for the financial support from the National Research Foundation (NRF) of Korea (NRF-2016M1A2A2940911, 2019R1A6A1A11044070).
PY - 2020/5/1
Y1 - 2020/5/1
N2 - An asymmetric wide-bandgap (WBG) nonfullerene acceptor (C6-IDTT-T) is developed by shearing one alkyl side-chain from a symmetrically alkyl-substituted indacenodithieno[3,2-b]thiophene (IDTT) core of the fused-ring electron acceptor 2C6-IDTT-T. These two acceptors both exhibit wide optical bandgaps over 1.8 eV. Investigations on the optical, electrochemical, and active layer morphology are conducted to understand the effect of asymmetric side chains on the electrical and photovoltaic properties. Compared with symmetric 2C6-IDTT-T, asymmetric C6-IDTT-T is found to exhibit redshifted absorption and higher electron mobility. As a result, the C6-IDTT-T blend with a thienothiophene-benzodithiophene copolymer (PTB7-Th) presents higher electron mobility and more balanced charge carrier transport, which leads to an enhanced power conversion efficiency of 8.51% for C6-IDTT-T-based device with a high open-circuit voltage of 1.052 V and a low energy loss of 0.60 eV.
AB - An asymmetric wide-bandgap (WBG) nonfullerene acceptor (C6-IDTT-T) is developed by shearing one alkyl side-chain from a symmetrically alkyl-substituted indacenodithieno[3,2-b]thiophene (IDTT) core of the fused-ring electron acceptor 2C6-IDTT-T. These two acceptors both exhibit wide optical bandgaps over 1.8 eV. Investigations on the optical, electrochemical, and active layer morphology are conducted to understand the effect of asymmetric side chains on the electrical and photovoltaic properties. Compared with symmetric 2C6-IDTT-T, asymmetric C6-IDTT-T is found to exhibit redshifted absorption and higher electron mobility. As a result, the C6-IDTT-T blend with a thienothiophene-benzodithiophene copolymer (PTB7-Th) presents higher electron mobility and more balanced charge carrier transport, which leads to an enhanced power conversion efficiency of 8.51% for C6-IDTT-T-based device with a high open-circuit voltage of 1.052 V and a low energy loss of 0.60 eV.
KW - alkyl tailoring strategy
KW - asymmetric nonfullerene acceptors
KW - efficiency
KW - open-circuit voltages
KW - wide bandgaps
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U2 - 10.1002/solr.202000061
DO - 10.1002/solr.202000061
M3 - Article
AN - SCOPUS:85084916445
VL - 4
JO - Solar RRL
JF - Solar RRL
SN - 2367-198X
IS - 5
M1 - 2000061
ER -