Published in
Elsevier, Synthetic Metals, 1-3(101), p. 606-607
DOI: 10.1016/s0379-6779(98)01232-6
Links
Tools
HREELS studies on the electronic structure of oligothiophene films
,
O. Pellegrino,
Da Silva,
J. D. Lopes Da Silva,
G. Horowitz,
F. Kouki,
F. Gamier,
M. Rei Vilar,
F. Garnier,
M. Rei Vilar
Full text: Download
Abstract
High resolution electron energy loss spectra (HREELS) were recorded for quaterthiophene (4T) films and compared to those of quinquethiophene (5T) and sexithiophene (6T). Excitonic gap was evaluated to be 2.64±0.02 eV. A second threshold appearing in HREELS but not in optical spectra, is assigned to excitation of charge transfer levels with thresholds of 3.60±0.02, 3.24±0.02 and 2.97±0.02 eV for 4T, 5T and 6T respectively. Losses between 1.0 and 2.3 eV in 4T and 5T are assigned to S 0→T n transitions. Resonance mechanisms are responsible for induced excitations in the oligothiophene film surfaces.