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Ultrafast conductivity in a low-band-gap polyphenylene and fullerene blend studied by terahertz spectroscopy

Nemec, Hynek LU ; Nienhuys, Han-Kwang ; Perzon, Erik ; Zhang, Fengling ; Inganas, Olle ; Kuzel, Petr and Sundström, Villy LU (2009) In Physical Review B (Condensed Matter and Materials Physics) 79(24).
Abstract
Time-resolved terahertz spectroscopy and Monte Carlo simulations of charge-carrier motion are used to investigate photoinduced transient conductivity in a blend of a low-band-gap polyphenylene copolymer and fullerene derivative. The optical excitation pulse generates free holes delocalized on polymer chains. We show that these holes exhibit a very high initial mobility as their initial excess energy facilitates their transport over defects (potential barriers) on polymer chains. The conductivity then drops down rapidly within 1 ps, and we demonstrate that this decrease occurs essentially by two mechanisms. First, the carriers loose their excess energy and they thus become progressively localized between the on-chain potential barriers-this... (More)
Time-resolved terahertz spectroscopy and Monte Carlo simulations of charge-carrier motion are used to investigate photoinduced transient conductivity in a blend of a low-band-gap polyphenylene copolymer and fullerene derivative. The optical excitation pulse generates free holes delocalized on polymer chains. We show that these holes exhibit a very high initial mobility as their initial excess energy facilitates their transport over defects (potential barriers) on polymer chains. The conductivity then drops down rapidly within 1 ps, and we demonstrate that this decrease occurs essentially by two mechanisms. First, the carriers loose their excess energy and they thus become progressively localized between the on-chain potential barriers-this results in a mobility decay with a rate of (180 fs)(-1). Second, carriers are trapped at defects (potential wells) with a capture rate of (860 fs)(-1). At longer time scales, populations of mobile and trapped holes reach a quasiequilibrium state and further conductivity decrease becomes very slow.</p>. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
polymer blends, photoconductivity, Monte Carlo methods, hole mobility, energy gap, fullerenes, terahertz wave spectra, time, resolved spectra
in
Physical Review B (Condensed Matter and Materials Physics)
volume
79
issue
24
publisher
American Physical Society
external identifiers
  • wos:000267699700102
  • scopus:68949127448
ISSN
1098-0121
DOI
10.1103/PhysRevB.79.245326
language
English
LU publication?
yes
additional info
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
245c6667-66e7-47b3-9795-5a4c5dc6fb25 (old id 1462372)
date added to LUP
2016-04-01 14:40:26
date last changed
2022-02-04 22:10:25
@article{245c6667-66e7-47b3-9795-5a4c5dc6fb25,
  abstract     = {{Time-resolved terahertz spectroscopy and Monte Carlo simulations of charge-carrier motion are used to investigate photoinduced transient conductivity in a blend of a low-band-gap polyphenylene copolymer and fullerene derivative. The optical excitation pulse generates free holes delocalized on polymer chains. We show that these holes exhibit a very high initial mobility as their initial excess energy facilitates their transport over defects (potential barriers) on polymer chains. The conductivity then drops down rapidly within 1 ps, and we demonstrate that this decrease occurs essentially by two mechanisms. First, the carriers loose their excess energy and they thus become progressively localized between the on-chain potential barriers-this results in a mobility decay with a rate of (180 fs)(-1). Second, carriers are trapped at defects (potential wells) with a capture rate of (860 fs)(-1). At longer time scales, populations of mobile and trapped holes reach a quasiequilibrium state and further conductivity decrease becomes very slow.&lt;/p&gt;.}},
  author       = {{Nemec, Hynek and Nienhuys, Han-Kwang and Perzon, Erik and Zhang, Fengling and Inganas, Olle and Kuzel, Petr and Sundström, Villy}},
  issn         = {{1098-0121}},
  keywords     = {{polymer blends; photoconductivity; Monte Carlo methods; hole mobility; energy gap; fullerenes; terahertz wave spectra; time; resolved spectra}},
  language     = {{eng}},
  number       = {{24}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B (Condensed Matter and Materials Physics)}},
  title        = {{Ultrafast conductivity in a low-band-gap polyphenylene and fullerene blend studied by terahertz spectroscopy}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.79.245326}},
  doi          = {{10.1103/PhysRevB.79.245326}},
  volume       = {{79}},
  year         = {{2009}},
}