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Exciton migration in a polythiophene: Probing the spatial and energy domain by line-dipole Forster-type energy transfer

Westenhoff, Sebastian LU ; Daniel, C; Friend, R H; Silva, C; Sundström, Villy LU and Yartsev, Arkady LU (2005) In Journal of Chemical Physics 122(9). p.1-094903
Abstract
We study exciton migration in low molecular weight poly[3-(2,5-dioctylphenyl)thiophene] in dilute solution by means of ultrafast spectroscopy and Monte Carlo simulations of resonance energy transfer using the line-dipole Forster approach. The model includes the build-up of polymer chains, site-selective exciton generation, and diffusion through incoherent energy transfer. Time-resolved, ensemble-averaged experimental data are reproduced, namely photoluminescence spectral migration and stimulated emission anisotropy decays measured by streak camera and femtosecond transient absorption spectroscopy under site-selective excitation conditions. Importantly, the relatively simple line-dipole Forster-type approach beyond the point-dipole... (More)
We study exciton migration in low molecular weight poly[3-(2,5-dioctylphenyl)thiophene] in dilute solution by means of ultrafast spectroscopy and Monte Carlo simulations of resonance energy transfer using the line-dipole Forster approach. The model includes the build-up of polymer chains, site-selective exciton generation, and diffusion through incoherent energy transfer. Time-resolved, ensemble-averaged experimental data are reproduced, namely photoluminescence spectral migration and stimulated emission anisotropy decays measured by streak camera and femtosecond transient absorption spectroscopy under site-selective excitation conditions. Importantly, the relatively simple line-dipole Forster-type approach beyond the point-dipole approximation reproduces both experiments quantitatively. Since explicit chain conformations are used in the model, the simulations yield a descriptive microscopic picture of exciton migration. The effective conjugation length (l(seg) = 2.9 nm, 7.4 monomer units) and the disorder of the chains (Omega = 0.8) are yielded as the only fitting parameters. We find an extra component that is not covered by our fits in anisotropy decays at early times for high excitation energies. This is interpreted within the context that the effective conjugation is limited by conformational disorder. (C) 2005 American Institute of Physics. (Less)
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organization
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type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
122
issue
9
pages
1 - 094903
publisher
American Institute of Physics
external identifiers
  • wos:000227483300077
  • scopus:22944467821
ISSN
0021-9606
DOI
10.1063/1.1855292
language
English
LU publication?
yes
id
be30015d-7e42-41af-b887-11e5036c20c4 (old id 151964)
date added to LUP
2007-07-04 08:49:55
date last changed
2017-08-20 03:36:00
@article{be30015d-7e42-41af-b887-11e5036c20c4,
  abstract     = {We study exciton migration in low molecular weight poly[3-(2,5-dioctylphenyl)thiophene] in dilute solution by means of ultrafast spectroscopy and Monte Carlo simulations of resonance energy transfer using the line-dipole Forster approach. The model includes the build-up of polymer chains, site-selective exciton generation, and diffusion through incoherent energy transfer. Time-resolved, ensemble-averaged experimental data are reproduced, namely photoluminescence spectral migration and stimulated emission anisotropy decays measured by streak camera and femtosecond transient absorption spectroscopy under site-selective excitation conditions. Importantly, the relatively simple line-dipole Forster-type approach beyond the point-dipole approximation reproduces both experiments quantitatively. Since explicit chain conformations are used in the model, the simulations yield a descriptive microscopic picture of exciton migration. The effective conjugation length (l(seg) = 2.9 nm, 7.4 monomer units) and the disorder of the chains (Omega = 0.8) are yielded as the only fitting parameters. We find an extra component that is not covered by our fits in anisotropy decays at early times for high excitation energies. This is interpreted within the context that the effective conjugation is limited by conformational disorder. (C) 2005 American Institute of Physics.},
  author       = {Westenhoff, Sebastian and Daniel, C and Friend, R H and Silva, C and Sundström, Villy and Yartsev, Arkady},
  issn         = {0021-9606},
  language     = {eng},
  number       = {9},
  pages        = {1--094903},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {Exciton migration in a polythiophene: Probing the spatial and energy domain by line-dipole Forster-type energy transfer},
  url          = {http://dx.doi.org/10.1063/1.1855292},
  volume       = {122},
  year         = {2005},
}