Vibrational study of hybrid systems based on graphene for solar cells

In this paper, the Infrared spectra of hybrid nanostructures obtained by confinement of oligothiophene derivatives in two sheets of graphene are calculated in the framework of spectral moment method, together with a bond-polarizability model. Minimum energy calculations are performed, using a convenient Lennard-Jones expression of the van der Waals intermolecular potential, to derive the optimum configurations of oligothiophene with graphene. Parallel configuration of thiophene molecules with respect to the graphene plane was considered. Infrared spectroscopy showed evidence of a significant charge transfer on the inserted oligothiophene. Both the G-band intensity and the low-frequency modes vanishing suggest a significant charge transfer between the bithiophene and the graphene.