Lattice thermal conductivity of graphene nanostructures

TL;DR

This study uses non-equilibrium molecular dynamics to analyze how graphene nanostructures like nanoribbons and nanorings conduct heat, revealing that nanorings can significantly suppress thermal conductivity at low temperatures and are less affected by edge imperfections.

Contribution

It provides new insights into the thermal transport properties of graphene nanostructures, especially the impact of shape and edge disorder on heat conduction.

Findings

Nanorings suppress lattice thermal conductivity more effectively than nanoribbons at low temperatures.

Edge disorder has minimal impact on heat transport in nanorings.

Hydrogen saturation of edges can be neglected in thermal conductivity considerations.

Abstract

Non-equilibrium molecular dynamics is used to investigate the heat current due to the atomic lattice vibrations in graphene nanoribbons and nanorings under a thermal gradient. We consider a wide range of temperature, nanoribbon widths up to 6nm and the effect of moderate edge disorder. We find that narrow graphene nanorings can efficiently suppress the lattice thermal conductivity at low temperatures (~100K), as compared to nanoribbons of the same width. Remarkably, rough edges do not appear to have a large impact on lattice energy transport through graphene nanorings while nanoribbons seem more affected by imperfections. Furthermore, we demonstrate that the effects of hydrogen-saturated edges can be neglected in these graphene nanostructures.