Origin of dispersive effects of the Raman D band in carbon materials

作者：Manyalibo J. Matthews, Marcos Assunção Pimenta, G. Dresselhaus, M. S. Dresselhaus, Morinobu Endo · 发表于：Physical review. B, Condensed matter · 年份：1999 · DOI：10.1103/physrevb.59.r6585 · 被引用次数：1005 · 研究领域：Diamond and Carbon-based Materials Research、Carbon Nanotubes in Composites、Mechanical and Optical Resonators

The origin and dispersion of the anomalous disorder-induced Raman band $(D$ band) observed in all ${\mathrm{sp}}^{2}$ hybridized disordered carbon materials near 1350 ${\mathrm{cm}}^{\ensuremath{-}1}$ is investigated as a function of incident laser energy. This effect is explained in terms of the coupling between electrons and phonons with the same wave vector near the K point of the Brillouin zone. The high dispersion is ascribed to the coupling between the optic phonons associated with the D band and the transverse acoustic branch. The large Raman cross section is due to the breathing motion of these particular phonons near the K point. Our model challenges the idea that the Raman D peak is due to laser-energy-independent features in the phonon density of states, but rather is due to a resonant Raman process.