A decrease in the D peak intensity with hole doping (and consequent reduction in Fermi level) has been observed previously and was attributed to a decrease in the number of scattering pathways for the D band due to the Pauli exclusion principle. The same reason is also responsible for the sharpening of the G peak as seen in Fig. , i.e. due to a blockage in phonon decay channels as a result of the lower electron-phonon coupling brought about by hole doping. These occur when the change in the Fermi level (∆𝐸 7 ) becomes larger than the half of phonon energy of the G peak (ℏωG), i.e. ~0.1 eV. Here ℏ is the reduced Planck constant.