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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
The dependence of graphene Raman D-band on carrier density
Junku Liu1, Qunqing Li, Yuan Zou
1State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University , Beijing 100084, China.
Abstract:
Raman spectroscopy has been an integral part of graphene research and can provide information about graphene structure, electronic characteristics, and electron-phonon interactions. In this study, the characteristics of the graphene Raman D-band, which vary with carrier density, are studied in detail, including the frequency, full width half-maximum, and intensity. We find the Raman D-band frequency increases for hole doping and decreases for electron doping. The Raman D-band intensity increases when the Fermi level approaches half of the excitation energy and is higher in the case of electron doping than that of hole doping. These variations can be explained by electron-phonon interaction theory and quantum interference between different Raman pathways in graphene. The intensity ratio of Raman D- and G-band, which is important for defects characterization in graphene, shows a strong dependence on carrier density.
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