TY - JOUR
T1 - The Impact of Acceptor-Acceptor Homocoupling on the Optoelectronic Properties and Photovoltaic Performance of PDTSQxff Low Bandgap Polymers
AU - Pirotte, G.
AU - Kesters, Jurgen
AU - Cardeynaels, Tom
AU - Verstappen, Pieter
AU - Lutsen, Laurence
AU - Champagne, Benoît
AU - Vanderzande, Dirk
AU - Maes, Wouter
N1 - Funding Information:
The calculations were performed on the computers of the Consortium des Équipements de Calcul Intensif (CECI, http://www.ceci-hpc.be), including those of the Technological Platform of High-Performance Computing, for which the authors gratefully acknowledge the financial support of the FNRS-FRFC (Conventions No. 2.4.617.07.F and 2.5020.11) and the University of Namur. The UHasselt co-authors thank Hasselt University and the Research Foundation – Flanders (FWO Vlaanderen) for the continuous financial support and postdoctoral fellowships for J.K. and P.V.
Funding Information:
The calculations were performed on the computers of the Consortium des ?quipements de Calcul Intensif (CECI, http://www.ceci-hpc.be), including those of the Technological Platform of High-Performance Computing, for which the authors gratefully acknowledge the financial support of the FNRS-FRFC (Conventions No. 2.4.617.07.F and 2.5020.11) and the University of Namur. The UHasselt co-authors thank Hasselt University and the Research Foundation ? Flanders (FWO Vlaanderen) for the continuous financial support and postdoctoral fellowships for J.K. and P.V.
Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Push-pull-type conjugated polymers applied in organic electronics do not always contain a perfect alternation of donor and acceptor building blocks. Misscouplings can occur, which have a noticeable effect on the device performance. In this work, the influence of homocoupling on the optoelectronic properties and photovoltaic performance of PDTSQxff polymers is investigated, with a specific focus on the quinoxaline acceptor moieties. A homocoupled biquinoxaline segment is intentionally inserted in specific ratios during the polymerization. These homocoupled units cause a gradually blue-shifted absorption, while the highest occupied molecular orbital energy levels decrease only significantly upon the presence of 75-100% of homocouplings. Density functional theory calculations show that the homocoupled acceptor unit generates a twist in the polymer backbone, which leads to a decreased conjugation length and a reduced aggregation tendency. The virtually defect-free PDTSQxff affords a solar cell efficiency of 5.4%, which only decreases substantially upon incorporating a homocoupling degree over 50%.
AB - Push-pull-type conjugated polymers applied in organic electronics do not always contain a perfect alternation of donor and acceptor building blocks. Misscouplings can occur, which have a noticeable effect on the device performance. In this work, the influence of homocoupling on the optoelectronic properties and photovoltaic performance of PDTSQxff polymers is investigated, with a specific focus on the quinoxaline acceptor moieties. A homocoupled biquinoxaline segment is intentionally inserted in specific ratios during the polymerization. These homocoupled units cause a gradually blue-shifted absorption, while the highest occupied molecular orbital energy levels decrease only significantly upon the presence of 75-100% of homocouplings. Density functional theory calculations show that the homocoupled acceptor unit generates a twist in the polymer backbone, which leads to a decreased conjugation length and a reduced aggregation tendency. The virtually defect-free PDTSQxff affords a solar cell efficiency of 5.4%, which only decreases substantially upon incorporating a homocoupling degree over 50%.
KW - Stille crosscoupling
KW - donor-acceptor polymers
KW - homocoupling
KW - polymer solar cells
KW - donor–acceptor polymers
UR - http://www.scopus.com/inward/record.url?scp=85045757818&partnerID=8YFLogxK
U2 - 10.1002/marc.201800086
DO - 10.1002/marc.201800086
M3 - Article
VL - 39
JO - Macromol Rapid Communications
JF - Macromol Rapid Communications
IS - 14
M1 - 1800086
ER -