Raman Spectroscopy in Graphene-Based Systems: Prototypes for Nanoscience and Nanometrology

Figure 3

Resonance process for the G band. On the left, the graphene phonon dispersion is shown, with a red-filled circle indicating the G band frequency and momentum. On the top right, the G band eigenvector is shown by the red arrows. On the bottom right, a zoom near the K point electronic dispersion shows the cone structure for the 𝜋 bands near the Fermi level (the Dirac cone). The wavy arrows indicate the incoming (green) and outgoing (red) photons. The electronic transitions induced by the incoming photon (green), the G band phonon (black), and the outgoing photon (red) are indicated by the vertical arrows.