Incorporation of alkylthio side chains on benzothiadiazole-based non-fullerene acceptors enables high-performance organic solar cells with over 16% efficiency
Y6-type non-fullerene acceptors (NFAs) with an acceptor-donor-acceptor′-donor-acceptor (A-D-A′-D-A) structure have been very popular in the field of organic solar cells (OSCs) due to their excellent performances. In this study, two novel NFAs, BTPS-4F and BTPS-4Cl were designed by incorporating unde...
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Published in | Journal of materials chemistry. A, Materials for energy and sustainability Vol. 8; no. 44; pp. 23239 - 23247 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
17.11.2020
Royal Society of Chemistry (RSC) |
Subjects | |
Online Access | Get full text |
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Summary: | Y6-type non-fullerene acceptors (NFAs) with an acceptor-donor-acceptor′-donor-acceptor (A-D-A′-D-A) structure have been very popular in the field of organic solar cells (OSCs) due to their excellent performances. In this study, two novel NFAs, BTPS-4F and BTPS-4Cl were designed by incorporating undecylthio side chains into a thienothiophene moiety and connecting it to two different halogenated 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile end groups (2F-IC and 2Cl-IC) respectively. When blended with a donor polymer, PM6, BTPS-4F-based devices achieved a high power conversion efficiency (PCE) of up to 16.2% with an open-circuit voltage (
V
OC
) of 0.82 V, a short-circuit current density (
J
SC
) of 25.2 mA cm
−2
and a fill factor (FF) of 0.78, while BTPS-4Cl-based devices achieved an inferior PCE of 13.5%. This is the first time alkylthio chains are employed on Y6-like NFAs to achieve high-performance OSCs. Subsequent characterization showed that the upshifted energy level of BTPS-4F and the better intermolecular packing in PM6:BTPS-4F blends are the major reasons for the enhanced performance of BTPS-4F-based devices over BTPS-4Cl-based ones. This work provides high-performance non-fullerene acceptors for OSCs and demonstrates a promising molecular design strategy that can effectively regulate their energy levels and morphology.
This is the first time alkylthio chains are employed on Y6-like NFAs to achieve organic solar cells of power conversion efficiency higher than 16%. |
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Bibliography: | 10.1039/d0ta08830g Electronic supplementary information (ESI) available. See DOI USDOE Contract DE-AC02-05CH11231 |
ISSN: | 2050-7488 2050-7496 |
DOI: | 10.1039/d0ta08830g |