• 文献标题:   Thermoelectric transport properties in graphene connected molecular junctions
  • 文献类型:   Article
  • 作  者:   RODRIGUEZ ST, GROSU I, CRISAN M, TIFREA I
  • 作者关键词:  
  • 出版物名称:   PHYSICA ELOWDIMENSIONAL SYSTEMS NANOSTRUCTURES
  • ISSN:   1386-9477 EI 1873-1759
  • 通讯作者地址:   Calif State Univ Fullerton
  • 被引频次:   3
  • DOI:   10.1016/j.physe.2017.09.022
  • 出版年:   2018

▎ 摘  要

We study the electronic contribution to the main thermoelectric properties of a molecular junction consisting of a single quantum dot coupled to graphene external leads. The system electrical conductivity (G), Seebeck coefficient (S), and the thermal conductivity (kappa), are numerically calculated based on a Green's function formalism that includes contributions up to the Hartree-Fock level. We consider the system leads to be made either of pure or gapped-graphene. To describe the free electrons in the gapped-graphene electrodes we used two possible scenarios, the massive gap scenario, and the massless gap scenario, respectively. In all cases, the Fano effect is responsible for a strong violation of the Wiedemann-Franz law and we found a substantial increase of the system figure of merit ZT due to a drastic reduction of the system thermal coefficient. In the case of gapped-graphene electrodes, the system figure of merit presents a maximum at an optimal value of the energy gap of the order of Delta/D similar to 0.002 (massive gap scenario) and Delta/D similar to 0.0026 (massless gap scenario). Additionally, for all cases, the system figure of merit is temperature dependent.