Thermal conductivity enhancement of defective graphene nanoribbons

Abstract

We study the heat transfer of graphene nanoribbons (GNRs) with different doped atoms (N, Si) and grain boundaries using non-equilibrium molecular dynamics and thermal relaxation method. It is found that even at low doping concentrations, with the increase of doping concentrations, the thermal conductivities of GNRs decrease greatly, and the thermal resistances of grain boundaries increase drastically. In addition, the mass difference between nitrogen and silicon atoms results in the difference in heat transfer. Further, we investigate the effect of the relative positions of nitrogen atoms and Stone-Wales (SW) defects on the thermal conductivity. We find that the thermal conductivity of GNR with doping atoms close to defects is higher than the thermal conductivity of GNR with doping atoms far away from defects, and when the dopant atoms are located in the heat flow path and close to more defects, it is better for heat transfer. Finally, it is found that the doping atoms can enhance the thermal conductivity when they are close to the heat source and heat sink, maybe this is the fact that doping atoms can inhibit phonon scattering in the heat source and heat sink.