Document Type
Article
Publication Date
8-26-2021
Publication Title
Nature Communications
Volume
12
Issue
1
First page number:
1
Last page number:
9
Abstract
The fission of singlet excitons into triplet pairs in organic materials holds great technological promise, but the rational application of this phenomenon is hampered by a lack of understanding of its complex photophysics. Here, we use the controlled introduction of vacancies by means of spacer molecules in tetracene and pentacene thin films as a tuning parameter complementing experimental observables to identify the operating principles of different singlet fission pathways. Time-resolved spectroscopic measurements in combination with microscopic modelling enables us to demonstrate distinct scenarios, resulting from different singlet-to-triplet pair energy alignments. For pentacene, where fission is exothermic, coherent mixing between the photoexcited singlet and triplet-pair states is promoted by vibronic resonances, which drives the fission process with little sensitivity to the vacancy concentration. Such vibronic resonances do not occur for endothermic materials such as tetracene, for which we find fission to be fully incoherent; a process that is shown to slow down with increasing vacancy concentration.
Controlled Subject
Fluorescence spectroscopy
Disciplines
Chemistry
File Format
File Size
1133 KB
Language
English
Rights
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Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Repository Citation
Zeiser, C.,
Cruz, C.,
Reichman, D. R.,
Seitz, M.,
Hagenlocher, J.,
Chronister, E. L.,
Bardeen, C. J.,
Tempelaar, R.,
Broch, K.
(2021).
Vacancy Control in Acene Blends Links Exothermic Singlet Fission to Coherence.
Nature Communications, 12(1),
1-9.
http://dx.doi.org/10.1038/s41467-021-25395-9