Semidefective Graphene/h-BN In-Plane Heterostructures: Enhancing Interface Thermal Conductance by Topological Defects

Two-dimensional (2D) in-plane heterostructures, whose interface thermal conductance (ITC) plays a crucial role in the thermal performance of nanostructured materials, will undoubtedly become the focus of the next-generation nanoelectronic devices. In this work, the semidefective graphene/hexagonal boron nitride in-plane heterostructures were innovatively proposed based on topological defects, and the thermal conductance across its interface was studied by molecular dynamics simulations. Surprisingly, the topological defects of a certain component in the heterostructure can significantly improve its ITC without changing the interfacial structure, and it is expected to be controlled by the defective concentration and the average temperature of the system. In particular, based on the different defective objects, the improvement of the ITC exhibits a radically different trend as the defective concentration increases. After the phonon activities were captured to explore the underlying physical mechanisms, it is found that the phonon coupling on both sides of the interface and the phonon localization effect of the heterostructure are two pivotal factors that determine the ITC of the heterostructure. The discovery of these results suggests a new path forward for improving or even controlling the ITC of the 2D in-plane heterostructures.