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The dynamics of triplet and singlet exciton populations in organic semiconductors offer interesting possibilities in improving optical device efficiency, while also attracting interest for future applications as manipulable states for quantum-state based computing. For technological applications, transduction of the exciton state is essential, thus detailed information on how the exciton dynamics affect device outputs is required. In this study, we measure the magnetic field response of the photocurrent in organic transistors to investigate the electrical signal resulting from singlet–triplet exciton dynamics. We find that controlling the orientation of the magnetic dipole orientation of the triplet by varying both the magnitude and orientation of the magnetic field with respect to single crystal axes in anti -2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene ( a diF TES ADT) allows us to manipulate the amount of current detected as a result of singlet fission.
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Optical probes of the quantum-entangled triplet-triplet state in a heteroacene dimer
The nature and extent of the spin-entanglement in the triplet-triplet biexciton with total spin zero in correlated-electron π-conjugated systems continues to be an enigma. Differences in the ultrafast transient absorption spectra of free triplets versus the triplet-triplet can give a measure of the entanglement. This, however, requires theoretical understandings of transient absorptions from the optical spin-singlet, the lowest spin-triplet exciton, as well as from the triplet-triplet state, whose spectra are often overlapping and hence difficult to distinguish. We present a many-electron theory of the electronic structure of the triplet-triplet, and of complete wavelength-dependent excited state absorptions (ESAs) from all three states in a heteroacene dimer of interest in the field of intramolecular singlet fission. The theory allows direct comparisons of ESAs with existing experiments as well as experimental predictions, and gives physical understandings of transient absorptions within a pictorial exciton basis that can be carried over to other experimental systems.
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- Award ID(s):
- 1764152
- PAR ID:
- 10098344
- Date Published:
- Journal Name:
- Physical review. B, Condensed matter
- Volume:
- 98
- Issue:
- 16
- ISSN:
- 1095-3795
- Page Range / eLocation ID:
- 165202
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/DOI: 10.1103/PhysRevB.98.165202
