Substituents on the end group subtle tuning the energy
levels and absorptions of small-molecule nonfullerene acceptors
Ke, X (Ke, Xin); Kan, B (Kan, Bin); Wan, XJ (Wan, Xiangjian); Wang, YC (Wang, Yunchuang); Zhang, YM (Zhang, Yamin); Li, CX (Li, Chenxi); Chen, YS (Chen, Yongsheng)[ 1 ]
DYES AND
PIGMENTS, 2018, 155: 241-248
DOI: 10.1016/j.dyepig.2018.03.061
WOS:000433650300033
Abstract
Two new
small-molecule nonfullerene acceptors containing methyl- and
fluorine-substituted 2-(2,3-dihydro-3-oxo-1H-inden-1-ylidene)propanedinitrile
(INCN) as end groups, namely, NFBDT-Me and NFBDT-F, were designed, synthesized
and applied in organic solar cells. The influence of the methyl and fluorine
groups on the absorption ability, energy levels, and photovoltaic performances
was fully investigated. Compared to their parent molecule NFBDT, these two
nonfullerene acceptors based devices exhibit higher PCEs with values of 11.00%
and 10.62%, respectively. For NFBDT-Me, the improvement of PCE is mainly
attributed to the higher V-oc, while for NFBDT-F, the increase of J(sc)
promotes the higher PCE. This suggests that appropriate manipulation of the
end-group substituents of these non-fullerene acceptors is a promising way to
enhance the PCEs of nonfullerene based OSCs.
