Layer and size dependence of thermal conductivity in multilayer graphene nanoribbons

Using nonequilibrium molecular dynamics method (NEMD), we have found that the thermal conductivity of multilayer graphene nanoribbons monotonously decreases with the increase of the number of layers which can be attributed to the phonon resonance effect of out-of-plane phonon modes. The reduction of thermal conductivity is proportional to the layer size, which is caused by the increase of phonon resonance. The results clearly show the dimensional evolution of thermal conductivity from quasi-one dimension to higher dimensions in graphene nanoribbons. -- Highlights: ► We investigate the thermal conductivity of multilayer GNRs using the NEMD. ► The thermal conductivity decreases with the increasing number of layers. ► The reduction of the thermal conductivity could be explained by phonon resonance. ► The difference between thermal conductivities increases with the layer size. ► The thermal conductivity can be controlled by changing number and size of layers.