Bossanyi, D.G. orcid.org/0000-0002-8804-802X, Matthiesen, M., Jayaprakash, R. orcid.org/0000-0002-2021-1601 et al. (3 more authors) (2024) Singlet fission is incoherent in pristine orthorhombic single crystals of rubrene: no evidence of triplet-pair emission. Faraday Discussions, 250. pp. 162-180. ISSN 1359-6640
Abstract
Singlet fission (SF) and its inverse, triplet–triplet annihilation (TTA), are promising strategies for enhancing photovoltaic efficiencies. However, detailed descriptions of the processes of SF/TTA are not fully understood, even in the most well-studied systems. Reports of the photophysics of crystalline rubrene, for example, are often inconsistent. Here we attempt to resolve these inconsistencies using time-resolved photoluminescence and transient absorption spectroscopy of ‘pristine’ rubrene orthorhombic single crystals. We find the reported time-resolved photoluminescence behaviour that hinted at triplet-pair emission is found only at specific sites on the crystals and likely arises from surface defects. Using transient absorption spectroscopy of the same crystals, we also observe no evidence of instantaneous generation of triplet-pair population with ∼100 fs excitation, independent of excitation wavelength (532 nm, 495 nm) or excitation angle. Our results suggest that SF occurs incoherently on a relatively slow (picosecond) timescale in rubrene single crystals, as expected from the original theoretical calculations. We conclude that the sub-100 fs formation of triplet pairs in crystalline rubrene films is likely to be due to static disorder.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 28 Nov 2023 16:04 |
Last Modified: | 25 Oct 2024 13:59 |
Status: | Published |
Publisher: | Royal Society of Chemistry (RSC) |
Refereed: | Yes |
Identification Number: | 10.1039/d3fd00150d |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:205965 |