Thermal conductivity and thermal rectification in graphene nanoribbons: a molecular dynamics study

We have used molecular dynamics based on the Brenner potential to calculate the thermal conductivity of graphene nanoribbons. For symmetrical nanoribbons, the calculated thermal conductivity is the similar order of magnitude of the experimentally measured value for graphene. We have investigated the effects of edge chirality and found that nanoribbons with zigzag edges have considerable larger thermal conductivity than that of nanoribbons with armchair edges. For asymmetric nanoribbons, we have found considerable thermal rectification. For example, for a 6nm-long triangular shaped nanoribbon, the thermal conductivity from the wider to the narrower end is nearly 2.5 times that from the narrower to the wider end. Furthermore, the thermal rectification can be significantly enhanced by increasing the size of the asymmetrical nanoribbon. Such rectification effects can be useful in nanoscale thermal management.