Electrical and Thermal Transport in Coplanar Polycrystalline Graphene-hBN Heterostructures

José Eduardo Barrios-Vargas, Bohayra Mortazavi, Aron W. Cummings, Rafael Martinez-Gordillo, Miguel Pruneda, Luciano Colombo, Timon Rabczuk, Stephan Roche

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)

Abstract

We present a theoretical study of electronic and thermal transport in polycrystalline heterostructures combining graphene (G) and hexagonal boron nitride (hBN) grains of varying size and distribution. By increasing the hBN grain density from a few percent to 100%, the system evolves from a good conductor to an insulator, with the mobility dropping by orders of magnitude and the sheet resistance reaching the MΩ regime. The Seebeck coefficient is suppressed above 40% mixing, while the thermal conductivity of polycrystalline hBN is found to be on the order of 30-120 Wm-1 K-1. These results, agreeing with available experimental data, provide guidelines for tuning G-hBN properties in the context of two-dimensional materials engineering. In particular, while we proved that both electrical and thermal properties are largely affected by morphological features (e.g., by the grain size and composition), we find in all cases that nanometer-sized polycrystalline G-hBN heterostructures are not good thermoelectric materials.

Original languageEnglish
Pages (from-to)1660-1664
Number of pages5
JournalNano Letters
Volume17
Issue number3
DOIs
Publication statusPublished - 2017 Mar 8

Keywords

  • Polycrystalline graphene
  • boron nitride
  • chemical vapor deposition
  • electrical properties
  • grain boundary
  • thermal properties
  • thermoelectrics

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Electrical and Thermal Transport in Coplanar Polycrystalline Graphene-hBN Heterostructures'. Together they form a unique fingerprint.

Cite this