We present the Raman bands of nano-graphene flakes (NG flakes) produced by oxidation of single-walled carbon nanotubes. These bands overlap with the defect-induced Raman modes of carbon nanotubes. This can lead to an overestimation of the defect density in the nanotubes. Here we analyze the line shape and the dispersion of this superimposing Raman band of NG flakes. Furthermore, we investigate the predicted Raman band of NG flakes next to the high-energy Raman modes ( and ) of the nanotubes.
Raman spectra of the defect-induced Raman mode of nanotubes after oxidation with the contribution of NG flakes.