Tunable anisotropic in-plane thermal transport of multilayer graphene induced by 2D empty space: Insights from interfaces

Abstract

The emergence of two-dimensional empty space (2D-ES) not only enriches the means of van der Waals integration, but also provides a new and reliable solution for structural design-driven performance modulation. Here, by applying the concept of 2D-ES-based periodic structure design to multilayer graphene, the large-range tunable in-plane anisotropic phonon thermal transport behavior was discovered by extensive molecular dynamics simulations. Through a series of in-depth frequency-dependent and in-and-out of plane decomposition phonon analysis, it is found that 2D-ES and its interfaces with different periodic properties exhibit exactly opposite effects on phonon thermal transport along two in-plane orientations, which is the fundamental reason for the existence of the above-mentioned anisotropic thermal transport and its modulation. These findings provide new insights into the realization of in-plane anisotropic thermal transport in quasi-2D materials, which may further inspire novel thermal management strategies.