Van der Waals stacked multilayer in-plane graphene/hexagonal boron nitride heterostructure: its interfacial thermal transport properties

TL;DR

This study investigates the interfacial thermal conductance of multilayer in-plane graphene/hexagonal boron nitride heterostructures, revealing layer-dependent behavior, the influence of stacking angle, and the potential for thermal regulation, challenging previous assumptions.

Contribution

It provides the first systematic analysis of interfacial thermal transport in multilayer in-plane Gr/h-BN heterostructures using NEMD simulations, highlighting new physical insights and control mechanisms.

Findings

ITC decreases with layer number, saturating at three layers

Multilayer heterostructures can outperform monolayers in thermal transport

Stacking angle and interlayer coupling significantly influence ITC

Abstract

Combining both vertical and in-plane two-dimensional (2D) heterostructures opens up the possibility to create an unprecedented architecture using 2D atomic layer building blocks. The thermal transport properties of such mixed heterostructures, critical to various applications in nanoelectronics, however, have not been thoroughly explored. Herein, we construct two configurations of multilayer in-plane graphene/hexagonal boron nitride (Gr/h-BN) heterostructures (i.e. mixed heterostructures) via weak van der Waals (vdW) interactions and systematically investigate the dependence of their interfacial thermal conductance (ITC) on the number of layers using non-equilibrium molecular dynamics (NEMD) simulations. The computational results show that the ITC of two configurations of multilayer in-plane Gr/h-BN heterostructures (MIGHHs) decrease with increasing layer number n and both saturate at n = 3. And surprisingly, we find that the MIGHH is more advantageous to interfacial thermal transport than the monolayer in-plane Gr/h-BN heterostructure, which is in strong contrast to the commonly held notion that the multilayer structures of Gr and h-BN suppress the phonon transmission. The underlying physical mechanisms for these puzzling phenomena are probed through the analyses of heat flux, temperature jump, stress concentration factor, overlap of phonon vibrational spectra and phonon participation ratio. In particular, by changing the stacking angle of MIGHH, a higher ITC can be obtained due to the thermal rectification behavior. Furthermore, we find that the ITC in MIGHH can be well-regulated by controlling the coupling strength between layers. Our findings here are of significance for understanding the interfacial thermal transport behaviors of multilayer in-plane Gr/h-BN heterostructure, and are expected to attract extensive interest in exploring its new physics and applications.