Phonon Transport of Zigzag/Armchair Graphene Superlattice Nanoribbons
Abstract
Nanostructured thermoelectric materials are promising for modulating physical properties to achieve high thermoelectric performance. In this paper, thermal transport properties of armchair/zigzag graphene superlattice nanoribbons (A/Z graphene SLNRs) are investigated by performing nonequilibrium molecular dynamics simulations. The target of the research is to realize low thermal conductivity by introducing single-vacancy point defects. Our simulations demonstrate that the thermal conductivity of A/Z graphene SLNRs depends nonmonotonically on periodic length. In addition, introducing single-vacancy point defects into the superlattice nanoribbons could decrease the phonon tunneling in superlattice nanoribbons, so that the thermal conductivity could be reduced further. Furthermore, a monotonic dependence of the thermal conductivity of A/Z graphene SLNRs with length of zigzag part in periodic length is discovered. This phenomenon is explained by performing phonon property analysis. Our simulations deliver a detailed phonon transport in A/Z graphene SLNRs and provide useful guidance on how to engineer the thermal transport properties of A/Z graphene SLNRs for applications of nanoribbon-related devices in thermoelectrics.
- Publication:
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International Journal of Thermophysics
- Pub Date:
- November 2018
- DOI:
- 10.1007/s10765-018-2448-2
- Bibcode:
- 2018IJT....39..125L
- Keywords:
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- Graphene superlattice nanoribbon;
- Molecular dynamics simulation;
- Phonon transport;
- Single-vacancy point defect