Origin of Efficient Inverted Nonfullerene Organic
Solar Cells: Enhancement of Charge Extraction and Suppression of Bimolecular
Recombination Enabled by Augmented Internal Electric Field
Yiwen Wang
Bo Wu
Zhenghui Wu
Zhaojue Lan
Yongfang Li
Maojie Zhang
Furong Zhu
10.1021/acs.jpclett.7b02308.s001
https://acs.figshare.com/articles/journal_contribution/Origin_of_Efficient_Inverted_Nonfullerene_Organic_Solar_Cells_Enhancement_of_Charge_Extraction_and_Suppression_of_Bimolecular_Recombination_Enabled_by_Augmented_Internal_Electric_Field/5496997
We
report our effort to unravel the origin of efficient operation
of nonfullerene organic solar cells (OSCs), based on a poly[4,8-bis(5-(2-ethylhexyl)
thiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-<i>alt</i>-(4-(2-ethylhexyl)-3-fluorothieno[3,4-<i>b</i>]thiophene-)-2-carboxylate-2-6-diyl)](PTB7-Th):3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno
[1,2-b:5,6-b′]dithiophene (ITIC) blend system. The effects
of buildup of space charges, charge extraction, and bimolecular recombination
processes on the performance and the stability of PTB7-Th:ITIC-based
regular and reverse configuration OSCs are analyzed. It is found that
the high-performing inverted PTB7-Th:ITIC OSCs benefit from the combined
effects of (1) suppression of bimolecular recombination enabled by
an augmented effective internal electric field and (2) improvement
of charge extraction by avoiding the holes passing through ITIC-rich
region, which would otherwise occur in a regular configuration cell.
The inverted PTB7-Th:ITIC OSCs possess a significant improvement in
the cell stability and a high power conversion efficiency of ∼8.0%,
which is >29% higher than that of an optimized regular configuration
control cell (6.1%).
2017-10-13 00:00:00
PTB 7-Th OSCs benefit
stability
power conversion efficiency
Augmented Internal Electric Field
configuration
Efficient Inverted Nonfullerene Organic Solar Cells
PTB 7-Th OSCs
charge extraction
ITIC
Bimolecular Recombination Enabled
recombination