期刊
PHYSICAL REVIEW B
卷 85, 期 16, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.85.165440
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资金
- Center on Nanostructuring for Efficient Energy Conversion (CNEEC) at Stanford University
- Energy Frontier Research Center
- US Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-SC0001060]
- Lundbeck Foundation
Using a first-principles approach we calculate the electron-phonon couplings in graphene for the transverse and longitudinal acoustic phonons. Analytic forms of the coupling matrix elements valid in the long-wavelength limit are found to give an almost quantitative description of the first-principles matrix elements even at shorter wavelengths. Using the analytic forms of the coupling matrix elements, we study the acoustic phonon-limited carrier mobility and quasiparticle lifetime observable in photoemission spectroscopy for temperatures 0-200 K and high carrier densities of 10(12)-10(13) cm(-2). We find that the intrinsic effective acoustic deformation potential of graphene is Xi(eff) = 6.8 eV and that the temperature dependence of the mobility mu similar to T-alpha in the Bloch-Gruneisen regime increases beyond an alpha = 4 dependence even in the absence of screening when the true coupling matrix elements are considered. The alpha > 4 temperature dependence of the mobility is found to originate in a similar temperature dependence of the relaxation time at the Fermi level. The large disagreement between our calculated deformation potential and those extracted from experimental measurements (18-29 eV) indicates that additional or modified acoustic phonon-scattering mechanisms are at play in experimental situations.
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