Infrared and Raman spectra of ABC-stacked few-layer graphene studied by first-principles calculations

Abstract

The infrared (IR) absorption spectra and resonant Raman spectra of ABC-stacked tri- and tetra-layer graphene are studied using the density functional theory. It is found that they exhibit very different characteristic peaks in their IR spectra and G-band resonant Raman spectra, compared with those of AB-stacked ones, caused by the different stacking sequence and interlayer coupling. The anisotropy of the IR spectra with respect to the direction of the light electric field is significant. The IR spectra are more sensitive to the stacking number when the electric field is perpendicular to the graphene plane due to the interlayer polarization. On the other hand, the calculated first-order G-band resonant Raman spectra are also found to be sensitive to the different stacking sequence and stacking number, though the sensitivity will decay as the stacking number increases. The high sensitivities make both IR and Raman spectra possible to identify the stacking sequence and number of few-layer graphene by comparing theory and experiment.