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Anomalous energy transfer dynamics due to torsional relaxation in a conjugated polymer

Westenhoff, Sebastian ; Beenken, Wichard J. D. ; Friend, Richard H. ; Greenham, Neil C. ; Yartsev, Arkady LU orcid and Sundström, Villy LU (2006) In Physical Review Letters 97(16).
Abstract
In isolated conjugated polymers two explanations are in discussion for the redshift of the emission on a picosecond time scale-exciton energy transfer (EET) between conjugated segments along the chains and conformational changes of these segments themselves, i.e., torsional relaxation. In order to resolve this question we perform femtosecond time-resolved transient absorption measurements of the energy relaxation of poly[3-(2,5-dioctylphenyl) thiophene] in toluene solution. We show that torsional relaxation can be distinguished from EET by site-selectively exciting low-energy conjugated segments. We present a unified model that integrates EET and torsional dynamics. In particular, comparison to ultrafast depolarization measurements shows... (More)
In isolated conjugated polymers two explanations are in discussion for the redshift of the emission on a picosecond time scale-exciton energy transfer (EET) between conjugated segments along the chains and conformational changes of these segments themselves, i.e., torsional relaxation. In order to resolve this question we perform femtosecond time-resolved transient absorption measurements of the energy relaxation of poly[3-(2,5-dioctylphenyl) thiophene] in toluene solution. We show that torsional relaxation can be distinguished from EET by site-selectively exciting low-energy conjugated segments. We present a unified model that integrates EET and torsional dynamics. In particular, comparison to ultrafast depolarization measurements shows that torsional dynamics cannot be neglected when analyzing EET dynamics and furthermore reveals that the exciton extends itself by about 2 monomer units during torsional relaxation. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
97
issue
16
publisher
American Physical Society
external identifiers
  • wos:000241405400051
  • scopus:33750192534
  • pmid:17155424
ISSN
1079-7114
DOI
10.1103/PhysRevLett.97.166804
language
English
LU publication?
yes
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The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)
id
255581f7-9850-4612-8990-d22abe00701d (old id 908307)
date added to LUP
2016-04-01 12:12:01
date last changed
2022-04-21 03:53:14
@article{255581f7-9850-4612-8990-d22abe00701d,
  abstract     = {{In isolated conjugated polymers two explanations are in discussion for the redshift of the emission on a picosecond time scale-exciton energy transfer (EET) between conjugated segments along the chains and conformational changes of these segments themselves, i.e., torsional relaxation. In order to resolve this question we perform femtosecond time-resolved transient absorption measurements of the energy relaxation of poly[3-(2,5-dioctylphenyl) thiophene] in toluene solution. We show that torsional relaxation can be distinguished from EET by site-selectively exciting low-energy conjugated segments. We present a unified model that integrates EET and torsional dynamics. In particular, comparison to ultrafast depolarization measurements shows that torsional dynamics cannot be neglected when analyzing EET dynamics and furthermore reveals that the exciton extends itself by about 2 monomer units during torsional relaxation.}},
  author       = {{Westenhoff, Sebastian and Beenken, Wichard J. D. and Friend, Richard H. and Greenham, Neil C. and Yartsev, Arkady and Sundström, Villy}},
  issn         = {{1079-7114}},
  language     = {{eng}},
  number       = {{16}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Letters}},
  title        = {{Anomalous energy transfer dynamics due to torsional relaxation in a conjugated polymer}},
  url          = {{http://dx.doi.org/10.1103/PhysRevLett.97.166804}},
  doi          = {{10.1103/PhysRevLett.97.166804}},
  volume       = {{97}},
  year         = {{2006}},
}