title: Dispersion of electron-phonon resonances in one-layer graphene and its demonstration in micro-Raman scattering.
abstract: In the present work, we used Raman spectroscopy as sensitive tool for characterization of dispersion of electron-phonon resonances in one-layer graphene. We analyzed Stokes and anti-Stokes components of the Raman spectra to investigate the temperature dependence of the graphene G-band on the power of exciting radiation. Appearance and drastic intensity increase of zone-edge D-like modes caused by introduction of structural defects and/or deformations in the graphene layer were observed in the Raman spectra at high powers of excitation. We investigated phonon dispersion of one-layer graphene for iTO phonon branch at K point along K-M direction, which is involved in double-resonance Raman scattering. Raman dispersion slope of D-band is in good agreement with results of theoretical calculations based on the Green's functions approach based on the screened electron-electron interaction. Deviation of the experimental iTO phonon frequency from the linear dependence on excitation energy was observed at excitation E(exc) = 3.81 eV. Self-consistent classification of phonon states according to the symmetry for all dispersion branches of one-layer graphene was carried out.
authors: V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 45 Nauky pr., 03028 Kyiv, Ukraine.
authors: V V
authors: VV
authors: Strelchuk
authors: A S
authors: AS
authors: Nikolenko
authors: V O
authors: VO
authors: Gubanov
authors: M M
authors: MM
authors: Biliy
authors: L A
authors: LA
authors: Bulavin
mesh_terms: D006108:Graphite / Q000737:chemistry*; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012542:Scattering, Radiation; D013059:Spectrum Analysis, Raman / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006108:Graphite