The thermal conductivity ($\kappa$) of graphene dramatically decreases once supported on a substrate, hindering its use for thermal management. To clarify the underlying mechanisms, we investigate the $\kappa$ of graphene on amorphous ${\mathrm{SiO}}_2$ by using molecular dynamics with particular attention to the graphene-substrate topography. Our analysis reveals that the suppression in $\kappa$ increases with the nonuniformity of the forces acting on graphene, which tends to increase as the substrate-surface roughness and graphene conformity increase. Our findings highlight the importance of the interfacial morphology on $\kappa$ and can provide guidance on the design of substrates to improve thermal transport through graphene.

• Received 2 February 2015

DOI:https://doi.org/10.1103/PhysRevApplied.4.014006

Source: http://link.aps.org/doi/10.1103/PhysRevApplied.4.014006