• 文献标题:   Magnetothermoelectric effects in graphene and their dependence on scatterer concentration, magnetic field, and band gap
  • 文献类型:   Article
  • 作  者:   KUNDU A, ALREFAE MA, FISHER TS
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF APPLIED PHYSICS
  • ISSN:   0021-8979 EI 1089-7550
  • 通讯作者地址:   Purdue Univ
  • 被引频次:   3
  • DOI:   10.1063/1.4979051
  • 出版年:   2017

▎ 摘  要

Using a semiclassical Boltzmann transport equation approach, we derive analytical expressions for electric and thermoelectric transport coefficients of graphene in the presence and absence of a magnetic field. Scattering due to acoustic phonons, charged impurities, and vacancies is considered in the model. Seebeck (S-xx) and Nernst (N) coefficients are evaluated as functions of carrier density, temperature, scatterer concentration, magnetic field, and induced band gap, and the results are compared to experimental data. Sxx is an odd function of Fermi energy, while N is an even function, as observed in experiments. The peak values of both coefficients are found to increase with the decreasing scatterer concentration and increasing temperature. Furthermore, opening a band gap decreases N but increases Sxx. Applying a magnetic field introduces an asymmetry in the variation of Sxx with Fermi energy across the Dirac point. The formalism is more accurate and computationally efficient than the conventional Green's function approach used to model transport coefficients and can be used to explore transport properties of other materials with Dirac cones such as Weyl semimetals. Published by AIP Publishing.