D-band Raman intensity of graphitic materials as a function of laser energy and crystallite size

The Raman intensity of the disorder-induced D-band in graphitic materials is calculated as a function of the in-plane size of the graphite nanoparticles (La) and as a function of the excitation laser energy. Matrix elements associated with the double resonance Raman processes, i.e., electron–photon, electron–phonon and electron–defect processes are calculated based on the tight binding method. The electron–defect interaction is calculated by considering the elastic scattering at the armchair edge of graphite, adopting a nanographite flake whose width is La. We compare the calculated results with the experimental results obtained from the spectra for different laser lines and La.