Interlayer coupling-induced controllable negative differential thermal resistance in graphene/h-BN van der Waals heterostructure

Abstract

The van der Waals (vdW) heterostructures employing graphene and hexagonal boron nitride (h-BN) have emerged as a typical system for building emergent two-dimensional devices, such as atomically thin transistors or capacitors. Herein, we study the nonlinear thermal transport in such vdW heterostructure by non-equilibrium molecular dynamics simulations. The results show that an obvious negative differential thermal resistance (NDTR) phenomenon can be observed under small temperature bias when the interlayer coupling becomes stronger. The vibrational spectra analysis manifests that the phonon filtering mechanism induced by interlayer coupling greatly hinders the interfacial thermal transport. To obtain the optimum conditions, the dependence of NDTR on the system length, lateral width, external temperature, and defect density is taken into account. Our findings extend the phonon filtering mechanism to thermal information processing.