Medium-Bandgap Small-Molecule Donors Compatible with Both
Fullerene and Nonfullerene Acceptors
Huo, Y (Huo, Yong)[ 1 ] ; Yan, CQ (Yan, Cenqi)[ 4 ] ; Kan, B (Kan, Bin)[ 5,6 ] ; Liu, XF (Liu, Xiao-Fei)[ 1 ] ; Chen, LC (Chen, Li-Chuan)[ 1 ] ; Hu, CX (Hu, Chen-Xia)[ 1 ] ; Lau, TK (Lau, Tsz-Ki)[ 7 ] ; Lu, XH (Lu, Xinhui)[ 7 ] ; Sun, CL (Sun, Chun-Lin)[ 1 ] ; Shao, XF (Shao, Xiangfeng)[ 1 ] ; Chen, YS (Chen, Yongsheng)[ 5,6 ] ; Zhan, XW (Zhan, Xiaowei)[ 4 ] ; Zhang, HL (Zhang, Hao-Li)[ 1,2,3 ]
ACS APPLIED
MATERIALS & INTERFACES, 2018, 10(11):
9587-9594
DOI: 10.1021/acsami.7b17961
WOS:000428356800046
Abstract
Much effort
has been devoted to the development of new donor materials for small-molecule
organic solar cells due to their inherent advantages of well-defined molecular
weight, easy purification, and good reproducibility in photovoltaic
performance. Herein, we report two small-molecule donors that are compatible
with both fullerene and nonfullerene acceptors. Both molecules consist of an
(E)-1,2-di(thiophen-2-ypethane-substituted (TVT-substituted)
benzo[1,2-b:4,5-b]dithiophene (BDT) as the central unit, and two rhodanine
units as the terminal electron-withdrawing groups. The central units are
modified with either alkyl side chains (DRBDT-TVT) or alkylthio side chains
(DRBDT-STVT). Both molecules exhibit a medium bandgap with complementary
absorption and proper energy level offset with typical acceptors like PC71BM
and IDIC. The optimized devices show a decent power conversion efficiency (PCE)
of 6.87% for small-molecule organic solar cells and 6.63% for nonfullerene all
small-molecule organic solar cells. Our results reveal that rationally designed
medium-bandgap small-molecule donors can be applied in high-performance
small-molecule organic solar cells with different types of acceptors.
