Polymorphs of α-sexithiophene probed by lattice phonon Raman microscopy

We report for the first time lattice phonon Raman spectra of the organic semiconductor α-sexithiophene (T6) measured with a Raman microprobe technique. We identify spectroscopically two polymorphs, as expected from available structural diffraction studies. Polarized spectra were recorded for symmetry assignment. A comparison of experimental data with Quasi Harmonic Lattice Dynamics calculations, performed starting from the experimental X-ray structures, is given.