Comparative studies of thermal conductivity for bilayer graphene with different potential functions in molecular dynamic simulations
Xingli Zhang, Zhiyue Chen, Hao Chen, Linyan Xu
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.