- Organic photovoltaics based on non-fullerene acceptors (NFAs) show record efficiency of 16 to 17% and increased photovoltage owing to the low driving force for interfacial charge-transfer. However, the low driving force potentially slows down charge generation, leading to a tradeoff between voltage and current. Here, we disentangle the intrinsic charge-transfer rates from morphology-dependent exciton diffusion for a series of polymer:NFA systems. Moreover, we establish the influence of the interfacial energetics on the electron and hole transfer rates separately. We demonstrate that charge-transfer timescales remain at a few hundred femtoseconds even at near-zero driving force, which is consistent with the rates predicted by Marcus theory in the normal region, at moderate electronic coupling and at low re-organization energy. Thus, in the design of highly efficient devices, the energy offset at the donor:acceptor interface can be minimized without jeopardizing the charge-transfer rate and without concerns about a current-voltageOrganic photovoltaics based on non-fullerene acceptors (NFAs) show record efficiency of 16 to 17% and increased photovoltage owing to the low driving force for interfacial charge-transfer. However, the low driving force potentially slows down charge generation, leading to a tradeoff between voltage and current. Here, we disentangle the intrinsic charge-transfer rates from morphology-dependent exciton diffusion for a series of polymer:NFA systems. Moreover, we establish the influence of the interfacial energetics on the electron and hole transfer rates separately. We demonstrate that charge-transfer timescales remain at a few hundred femtoseconds even at near-zero driving force, which is consistent with the rates predicted by Marcus theory in the normal region, at moderate electronic coupling and at low re-organization energy. Thus, in the design of highly efficient devices, the energy offset at the donor:acceptor interface can be minimized without jeopardizing the charge-transfer rate and without concerns about a current-voltage tradeoff.…
MetadatenAuthor details: | Yufei ZhongORCiD, Martina CausaGND, Gareth John MooreORCiD, Philipp KrauspeGND, Bo Xiao, Florian GüntherORCiD, Jonas KublitskiORCiDGND, Eyal BarOr, Erjun ZhouORCiD, Natalie BanerjiORCiD |
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URN: | urn:nbn:de:kobv:517-opus4-511936 |
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DOI: | https://doi.org/10.25932/publishup-51193 |
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ISSN: | 1866-8372 |
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Title of parent work (German): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe |
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Publication series (Volume number): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (1422) |
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Publication type: | Postprint |
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Language: | English |
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Date of first publication: | 2020/02/11 |
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Publication year: | 2020 |
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Publishing institution: | Universität Potsdam |
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Release date: | 2024/03/13 |
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Tag: | Donor-Acceptor (DA) interface; donor; efficiency; electron-transfer; energy; impact; organic solar cell; photovoltaics; seperation; transfer dynamics |
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Issue: | 1 |
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Article number: | 833 |
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Number of pages: | 12 |
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Source: | Nat Commun 11, 833 (2020). https://doi.org/10.1038/s41467-020-14549-w |
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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 / Green Open-Access |
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License (German): | CC-BY - Namensnennung 4.0 International |
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External remark: | Bibliographieeintrag der Originalveröffentlichung/Quelle |
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