Gjergji Sini, Marcel Schubert, Chad Risko, Steffen Roland, Olivia P. Lee, Zhihua Chen, Thomas V. Richter, Daniel Dolfen, Veaceslav Coropceanu, Sabine Ludwigs, Ullrich Scherf, Antonio Facchetti, Jean M. J. Frechet, Dieter Neher
- Fullerene-based acceptors have dominated organic solar cells for almost two decades. It is only within the last few years that alternative acceptors rival their dominance, introducing much more flexibility in the optoelectronic properties of these material blends. However, a fundamental physical understanding of the processes that drive charge separation at organic heterojunctions is still missing, but urgently needed to direct further material improvements. Here a combined experimental and theoretical approach is used to understand the intimate mechanisms by which molecular structure contributes to exciton dissociation, charge separation, and charge recombination at the donor-acceptor (D-A) interface. Model systems comprised of polythiophene-based donor and rylene diimide-based acceptor polymers are used and a detailed density functional theory (DFT) investigation is performed. The results point to the roles that geometric deformations and direct-contact intermolecular polarization play in establishing a driving force ( energyFullerene-based acceptors have dominated organic solar cells for almost two decades. It is only within the last few years that alternative acceptors rival their dominance, introducing much more flexibility in the optoelectronic properties of these material blends. However, a fundamental physical understanding of the processes that drive charge separation at organic heterojunctions is still missing, but urgently needed to direct further material improvements. Here a combined experimental and theoretical approach is used to understand the intimate mechanisms by which molecular structure contributes to exciton dissociation, charge separation, and charge recombination at the donor-acceptor (D-A) interface. Model systems comprised of polythiophene-based donor and rylene diimide-based acceptor polymers are used and a detailed density functional theory (DFT) investigation is performed. The results point to the roles that geometric deformations and direct-contact intermolecular polarization play in establishing a driving force ( energy gradient) for the optoelectronic processes taking place at the interface. A substantial impact for this driving force is found to stem from polymer deformations at the interface, a finding that can clearly lead to new design approaches in the development of the next generation of conjugated polymers and small molecules.…
MetadatenAuthor details: | Gjergji SiniORCiD, Marcel SchubertORCiD, Chad Risko, Steffen RolandORCiDGND, Olivia P. Lee, Zhihua Chen, Thomas V. Richter, Daniel Dolfen, Veaceslav Coropceanu, Sabine Ludwigs, Ullrich ScherfORCiDGND, Antonio Facchetti, Jean M. J. FrechetORCiD, Dieter NeherORCiDGND |
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DOI: | https://doi.org/10.1002/aenm.201702232 |
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ISSN: | 1614-6832 |
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ISSN: | 1614-6840 |
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Title of parent work (English): | Advanced energy materials |
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Publisher: | Wiley-VCH |
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Place of publishing: | Weinheim |
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Publication type: | Article |
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Language: | English |
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Date of first publication: | 2018/01/22 |
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Publication year: | 2018 |
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Release date: | 2021/12/08 |
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Tag: | donor-acceptor interfaces; energy gradients; geometrical deformations; nonfullerene acceptors; organic photovoltaics; photocurrent generation; polymer solar cells |
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Volume: | 8 |
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Issue: | 12 |
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Number of pages: | 15 |
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Funding institution: | University of Kentucky; Department of the Navy, Office of Naval ResearchOffice of Naval Research [N00014-16-1-2985, N00014-14-1-0580, N00014-16-1-2520]; German Science FoundationGerman Research Foundation (DFG) [SPP 1355] |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
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DDC classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
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Peer review: | Referiert |
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Publishing method: | Open Access / Bronze Open-Access |
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