Raman scattering of molecular graphenes

A simplified theoretical approach for modeling the off-resonance Raman scattering of molecular models of confined graphene (polycyclic aromatic hydrocarbons, PAHs) is presented and compared with the results from density functional theory calculations. This theoretical analysis not only allows for a quick estimate of the Raman scattering activity, but also correlates the Raman response to simple quantities directly linked to the molecular electronic structure. Owing to its simplicity and computational convenience the model can be applied to extended graphitic systems. The results of the Hueckel calculations on the off-resonance Raman bond polarizability parameters of nanometer sized armchair and zizgag graphene flakes are shown.