Ternary Organic Solar Cells With 12.8% Efficiency Using
Two Nonfullerene Acceptors With Complementary Absorptions
Kan, B (Kan, Bin)[ 1,2,3 ] ; Yi, YQQ (Yi, Yuan-Qiu-Qiang)[ 1,2,3 ] ; Wan, XJ (Wan, Xiangjian)[ 1,2,3 ] ; Feng, HR (Feng, Huanran)[ 1,2,3 ] ; Ke, X (Ke, Xin)[ 1,2,3 ] ; Wang, YB (Wang, Yanbo)[ 1,2,3 ] ; Li, CX (Li, Chenxi)[ 1,2,3 ] ; Chen, YS (Chen, Yongsheng)[ 1,2,3 ]
ADVANCED
ENERGY MATERIALS, 2018, 8(22): 文献号: 1800424
DOI: 10.1002/aenm.201800424
WOS:000440805400010
Abstract
A new
small-molecule acceptor (2,9-bis(2-methylene-(3(1,1-dicyanomethylene) benz[f]
indanone))
7,12-dihydro-(4,4,10,10-tetrakis(4-hexylphenyl)-5,11-diocthylthieno-[3', 2':
4,5] cyclopenta[1,2-b] thieno[2., 3.: 3', 4'] cyclopenta[1', 2': 4,5]
thieno[2,3-f] [1] benzothiophene) (NNBDT) based on naphthyl-fused indanone ending
units is reported. This molecule shows a narrow optical bandgap of 1.43 eV and
effective absorption in the range of 700-870 nm. The devices based on
poly[(2,6-(4,8-bis(5-(2-ethylhexyl) thiophen-2-yl)-benzo[1,2-b: 4,5-b']
dithiophene))alt-(5,5-(1', 3'-di-2-thienyl-5', 7'-bis(2-ethylhexyl) benzo[1',
2'-c: 4', 5'-c'] dithiophene4,8-dione))] (PBDB-T): NNBDT yield a power
conversion efficiency of 11.7% with a low energy loss of 0.55 eV and a high
fill factor (FF) of 71.7%. Another acceptor (2,9-bis(2-methylene-(3(1,1-dicyanomethylene)
benz[f] indanone)) 7,12-dihydro-4,4,7,7,12,12-hexaoctyl-4H-cyclopenta[2., 1.:
5,6; 3., 4.: 5', 6'] diindeno[1,2b: 1', 2'-b'] dithiophene (FDNCTF) is
introduced as the third component to fabricate ternary devices. The two acceptors
(NNBDT and FDNCTF) possess complementary absorption, same molecular
orientation, and well-miscible behavior. It is found that there exists a
nonradiative energy transfer process from FDNCTF to NNBDT. The fullerene-free
ternary cells based on PBDBT: NNBDT: FDNCTF achieve a high efficiency of 12.8%
with an improved short circuit current near 20 mA cm(-2) in contrast to the
binary devices. The result represents the best performance for fullerene-free
ternary solar cells reported to date and highlights the potential of ternary
solar cells.
