First-principles study of heat transport properties of graphene nanoribbons

TL;DR

This study uses first-principles calculations to analyze how edge structure and passivation affect heat transport in graphene nanoribbons, revealing anisotropic phonon behavior and edge effects on thermal conductance.

Contribution

It combines density-functional theory and nonequilibrium Green's function methods to systematically compare thermal transport in armchair and zigzag graphene nanoribbons, highlighting edge and passivation influences.

Findings

Zigzag ribbons have higher thermal conductance than armchair ribbons.

Phonon dispersion anisotropy causes differences in thermal transport.

Edge passivation modifies atomic structure and phonon transport.

Abstract

We combine density-functional theory and the nonequilibrium Green's function method to study the thermal conductance of graphene nanoribbons with armchair and zigzag edges. Zigzag ribbons have higher thermal conductance than armchair ribbons of comparable widths due to an anisotropy in phonon dispersion for graphene nanoribbons: low-frequency bands in zigzag ribbons are more dispersive than those in armchair ribbons. The edges with and without hydrogen-passivation modify the atomic structure and ultimately influence the phonon thermal transport differently for the two ribbon types.