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The electronic states of polyfluorene copolymers with alternating donor-acceptor units

Jespersen, Kim LU ; Beenken, Wichard LU ; Zausjitsyn, Yuri LU ; Yartsev, Arkady LU ; Andersson, Mats; Pullerits, Tönu LU and Sundström, Villy LU (2004) In Journal of Chemical Physics 121(24). p.12613-12617
Abstract
We calculate the electronic states of the low bandgap polyfluorene-based copolymer DiO-PFDTBT, which consists of alternating 9,9-dioctyl-9H-fluorene and 4,7-di-thiophen-2-ylbenzo[1,2,5]thiadiazole (TBT) units, and compare with the steady-state absorption, emission, and excitation spectrum. Using the semiempirical quantum-chemical (ZINDO) method we can assign the characteristic bands of the "camel-back" absorption spectrum to one charge transfer state at lower energy localized on the TBT unit, and one delocalized excitonic state at higher energy corresponding to the -conjugated electron system. Additional "dark" charge transfer states in the gap between these bands have been revealed. Calculations are also made on the red light emitting... (More)
We calculate the electronic states of the low bandgap polyfluorene-based copolymer DiO-PFDTBT, which consists of alternating 9,9-dioctyl-9H-fluorene and 4,7-di-thiophen-2-ylbenzo[1,2,5]thiadiazole (TBT) units, and compare with the steady-state absorption, emission, and excitation spectrum. Using the semiempirical quantum-chemical (ZINDO) method we can assign the characteristic bands of the "camel-back" absorption spectrum to one charge transfer state at lower energy localized on the TBT unit, and one delocalized excitonic state at higher energy corresponding to the -conjugated electron system. Additional "dark" charge transfer states in the gap between these bands have been revealed. Calculations are also made on the red light emitting polyfluorene-based copolymer poly(fluorene-co-benzothiadiazole) (F8BT), which contains benzo[1,2,5]thiadiazole instead of TBT. The nature of the electronic states in F8BT and DiO-PFDTBT are found to be qualitatively the same. ©2004 American Institute of Physics. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
121
issue
24
pages
12613 - 12617
publisher
American Institute of Physics
external identifiers
  • wos:000225714500057
  • scopus:18844446329
ISSN
0021-9606
DOI
10.1063/1.1817873
language
English
LU publication?
yes
id
706b894c-aac0-4f9a-89f5-caa27d35d137 (old id 141453)
date added to LUP
2007-07-03 13:44:09
date last changed
2017-10-08 03:37:31
@article{706b894c-aac0-4f9a-89f5-caa27d35d137,
  abstract     = {We calculate the electronic states of the low bandgap polyfluorene-based copolymer DiO-PFDTBT, which consists of alternating 9,9-dioctyl-9H-fluorene and 4,7-di-thiophen-2-ylbenzo[1,2,5]thiadiazole (TBT) units, and compare with the steady-state absorption, emission, and excitation spectrum. Using the semiempirical quantum-chemical (ZINDO) method we can assign the characteristic bands of the "camel-back" absorption spectrum to one charge transfer state at lower energy localized on the TBT unit, and one delocalized excitonic state at higher energy corresponding to the -conjugated electron system. Additional "dark" charge transfer states in the gap between these bands have been revealed. Calculations are also made on the red light emitting polyfluorene-based copolymer poly(fluorene-co-benzothiadiazole) (F8BT), which contains benzo[1,2,5]thiadiazole instead of TBT. The nature of the electronic states in F8BT and DiO-PFDTBT are found to be qualitatively the same. ©2004 American Institute of Physics.},
  author       = {Jespersen, Kim and Beenken, Wichard and Zausjitsyn, Yuri and Yartsev, Arkady and Andersson, Mats and Pullerits, Tönu and Sundström, Villy},
  issn         = {0021-9606},
  language     = {eng},
  number       = {24},
  pages        = {12613--12617},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {The electronic states of polyfluorene copolymers with alternating donor-acceptor units},
  url          = {http://dx.doi.org/10.1063/1.1817873},
  volume       = {121},
  year         = {2004},
}