• 文献标题:   Thermoelectric properties of gapped bilayer graphene
  • 文献类型:   Article
  • 作  者:   SUSZALSKI D, RUT G, RYCERZ A
  • 作者关键词:   graphene, bilayer graphene, thermoelectric, seebeck effect, ballistic transport
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984 EI 1361-648X
  • 通讯作者地址:   Jagiellonian Univ
  • 被引频次:   2
  • DOI:   10.1088/1361-648X/ab2d0c
  • 出版年:   2019

▎ 摘  要

Unlike in conventional semiconductors, both the chemical potential and the band gap in bilayer graphene (BLG) can be tuned via application of external electric field. Among numerous device implications, this property also designates BLG as a candidate for high-performance thermoelectric material. In this theoretical study we have calculated the Seebeck coefficients for abrupt interface separating weakly- and heavily-doped areas in BLG, and for a more realistic rectangular sample of mesoscopic size, contacted by two electrodes. For a given band gap (Delta) and temperature (T) the maximal Seebeck coefficient is close to the Goldsmid- Sharp value vertical bar S vertical bar(GS)(max) = Delta/(2eT), the deviations can be approximated by the asymptotic expression vertical bar S vertical bar(GS)(max) - vertical bar S vertical bar(max) = (kappa(B)/e) x [1/2 ln u + ln 2 - 1/2 + O(u(-1))], with the electron charge -e, the Boltzmann constant kappa(B), and u = Delta(2 kappa T-B) >> 1. Surprisingly, the effects of trigonal warping term in the BLG low-energy Hamiltonian are clearly visible at few-Kelvin temperatures, for all accessible values of Delta 3) when a rigid substrate suppresses out-of-plane vibrations, reducing the contribution from ZA phonons to the thermal conductivity.