Comparative studies of thermal conductivity for bilayer graphene with different potential functions in molecular dynamic simulations

Abstract

Potential functions play an essential role in the heat transport of the nano-scale materials when they are investigated by molecular dynamics simulations. In this paper, the thermal conductivity of bilayer graphene (BLG) is calculated by the non-equilibrium molecular dynamics using different in-layer and interlayer potentials. It is found that the Kolmogorov-Crespi (K-C) potential gives a lower thermal conductivity than Lennard-Jones (L-J) potential when they are used to describe the interlayer interaction of C–C atoms. The calculation results using K-C potential show that compared to L-J potential, there is about 10% reduction in thermal conductivity of BLG. For the in-layer interaction potentials, the TERSOFF potential provides much higher thermal conductivity than it from REBO and AIREBO potentials. In addition, the thermtal conductivity of BLG shows notably different temperature-dependence and same size effect calculated with various potentials. Based on the phonon density of states and phonon dispersion calculations, we find the simulation results calculated by K-C + REBO potential are in excellent agreement with the experimental values.