Unoriented and highly oriented films of poly(octylthiophene) (POT) have been studied by optical-absorption measurements and Raman scattering. Optical absorption was analyzed using a vibronic model improved by the explicit evaluation of transition-matrix elements. The average conjugation length of POT at room temperature was estimated to be four thiophene rings. After stretch orientation, the ordered region in the material and the conjugation length in the ordered region increased. A clear dispersion and a strong anisotropy were observed for the Raman line of the amplitude mode, which is interpreted by the conjugation-length model.
ASJC Scopus subject areas
- Condensed Matter Physics