• 文献标题:   Simulation of bipolar charge transport in graphene on h-BN
  • 文献类型:   Article
  • 作  者:   COCO M, NASTASI G
  • 作者关键词:   graphene, discontinuous galerkin method, bipolar charge transport, 82d37, 82c70, 65m60, 82c80
  • 出版物名称:   COMPELTHE INTERNATIONAL JOURNAL FOR COMPUTATION MATHEMATICS IN ELECTRICAL ELECTRONIC ENGINEERING
  • ISSN:   0332-1649
  • 通讯作者地址:   Univ Catania
  • 被引频次:   3
  • DOI:   10.1108/COMPEL-08-2019-0311 EA JAN 2020
  • 出版年:   2020

▎ 摘  要

Purpose The purpose of this paper is to simulate charge transport in monolayer graphene on a substrate made of hexagonal boron nitride (h-BN). This choice is motivated by the fact that h-BN is one of the most promising substrates on account of the reduced degradation of the velocity due to the remote impurities. Design/methodology/approach The semiclassical Boltzmann equations for electrons in the monolayer graphene are numerically solved by an approach based on a discontinuous Galerkin (DG) method. Both the conduction and valence bands are included, and the inter-band scatterings are taken into account as well. Findings The importance of the inter-band scatterings is accurately evaluated for several values of the Fermi energy, addressing the issue related to the validity of neglecting the generation-recombination terms. It is found out that the inclusion of the inter-band scatterings produces sizable variations in the average values, like the current density, at zero Fermi energy, whereas, as expected, the effect of the inter-band scattering becomes negligible by increasing the absolute value of the Fermi energy. Originality/value As observed in Majorana et al. (2019), the use of a Direct Simulation Monte Carlo (DSMC) approach, which properly describes the inter-band scatterings, is computationally very expensive because the valence band is highly populated and a huge number of particles is needed. Even by simulating holes instead of electrons does not overcome the problem because there is a certain degree of ambiguity in the generation and recombination terms of electron-hole pairs. The DG approach, used in this paper, does not suffer from the previous drawbacks and requires a reasonable computing effort.