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 MoS 2 , 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-MoS 2 bilayer heterostructure via molecular dynamics simulation. It is found that the in-plane thermal conductivity l B of the GE-MoS 2 bilayer can be approximated by that of an isolated monolayer GE. The l B of an infinitely long GE-MoS 2 bilayer is calculated to be 1037 W m À1 K À1 , while its out-of-plane interface thermal conductance G is obtained as 5.81 MW m À2 K À1 . The increase in the interface coupling strengths can dramatically increase G but has little effect on l B . On the other hand, G also increases with temperature because of the enhanced phonon coupling between GE and MoS 2 . 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.

Interfacial thermal conductance in graphene/black phosphorus heterogeneous structures

“…It features an almost linear dependence relationship for the Umklapp processes which play the critical role in the heat transport. [31][32] This tendency is in good agreement with those for interfaces between graphene and SiO 2 or polymer materials. To get the substantial insight and a detailed understanding of the heat transfer mechanisms at the interface, we investigate the vibration spectra density of states at interfaces by analyzing the correlations of atomic vibrations.…”

“…One is the compression on the multi-layer structures reduces the interlayer distance, and therefore increases the interlayer interactions, i.e., enhances the LJ interactions and coupling between interlayers and leads to the increasing the heat transport performance. 4,30,32 The other is that increasing shear interaction between interlayers will increase the thermal transport contribution from in-plane phonons. The power spectra of carbon and phorphorous atoms in graphene and BP layers at the interface under various strains are shown in Figure 11.…”

Thickness-dependent Kapitza resistance in multilayered graphene and other two-dimensional crystals

“…[25], we first discuss the case for the two-layer crystal [see Fig. 1(b)], which can be a homogeneous material like bilayer graphene or a composite like a graphene/MoS 2 vdW heterostructure [33]. We do not assume that the two layers are identical for the sake of generality.…”

Stacking order dependent mechanical properties of graphene/MoS2 bilayer and trilayer heterostructures

“…15 However, weak mechanical strength and susceptibility to oxidation limit the suitability of SL-MoS 2 and ML-MoS 2 for device applications. To circumvent this issue, recently, there have been efforts to combine these TMDC materials with graphene, which has exceptional mechanical properties and oxidation resistance, for applications such as ultra-gain photodetectors, 16 thermal interface materials, 17 and superlubric materials. 18 These studies highlight the need for a deeper understanding of the mechanical properties of these heterostructures, which would be necessary to integrate them into applications such as flexible electronics, piezoelectric devices, and optoelectronics.…”