Thermal transport in a graphene–MoS2 bilayer heterostructure: a molecular dynamics study

Abstract

With the availability of various types of two-dimensional materials such as graphene (GE) and MoS₂, intensive efforts have been devoted to their van der Waals heterostructures obtained by vertically stacking them together for novel functionalities and applications. The thermal transport behavior of these heterostructures plays a pivotal role in determining their functional performance. This work studies the thermal transport in a GE–MoS₂ bilayer heterostructure via molecular dynamics simulation. It is found that the in-plane thermal conductivity λ_B of the GE–MoS₂ bilayer can be approximated by that of an isolated monolayer GE. The λ_B of an infinitely long GE–MoS₂ bilayer is calculated to be 1037 W m⁻¹ K⁻¹, while its out-of-plane interface thermal conductance G is obtained as 5.81 MW m⁻² K⁻¹. The increase in the interface coupling strengths can dramatically increase G but has little effect on λ_B. On the other hand, G also increases with temperature because of the enhanced phonon coupling between GE and MoS₂. This study is helpful for understanding the interface thermal transport behaviors of novel van der Waals heterostructures and could provide guidance for optimal design and control of their thermal properties.