| Issue |
J. Chim. Phys.
Volume 89, 1992
|
|
|---|---|---|
| Page(s) | 1091 - 1096 | |
| DOI | https://doi.org/10.1051/jcp/1992891091 | |
| Published online | 29 May 2017 | |
Modélisation des spectres infrarouge et Raman du polythiophène dopé
1 Groupe de Dynamique des Phases Condensées, URA 233, France ;
2 Laboratoire de Chimie Générale, Université Montpellier II, Sciences et Techniques du Languedoc, place E Bataillon, 34095 Montpellier Cedex 5, France.
Des spectres infrarouge et Raman à divers taux de dopage ont été réalisés sur de nouveaux films de polythiophène présentant une large gamme de longueurs de conjugaison. A l’aide de la méthode des moments spectraux on a pu modéliser l’ensemble des faits observés sur les spectres. En particulier, les effets dûs au dopage, tels que des raies intenses en dehors des modes propres de la chaîne parfaite, sont bien reproduits par l’adjonction d’un bipolaron dans le cadre d’un modèle moléculaire.
Abstract
New infrared and Raman spectra on undoped and doped polythiophene films, obtained in various synthesis conditions, were recorded. The samples present a broad distribution of conjugation lengths. To explain all the observed spectra within a discrete force field model we use the spectral moments method : not only the calculated frequencies are very close to the experimental data but the intensities and the behaviour with conjugation length of the infrared and Raman lines are in fair agreement for undoped and doped polythiophene. Particularly the emergence upon doping of four intense lines at 1032, 1117, 1203 and 1334 cm-1 and other features less intense in infrared, and in isotropic Raman scattering the decreasing of the intensity of all lines are nicely reproduced by the addition of a bipolaron in the model The infrared activity is very well represented with a simple tensor charge model without taking explicitely into account the fluctuation of the charge density.
© Elsevier, Paris, 1992