Effect of Defects on the Thermal Transport across the Graphene/Hexagonal Boron Nitride Interface

Abstract

Owing to its extraordinary physical properties and potential for next generation nanoelectronics, the in-plane graphene/hexagonal boron nitride (Gr/h-BN) heterostructure has been fabricated recently and gained a lot of attention. The defects located at the interface such as vacancies, topological defects are inevitable during the growth process. However, the effects of the defects on the interfacial thermal conductance between the Gr/h-BN interface have not well understood. In this work, the effects of defects on the interfacial thermal conductance across the Gr/h-BN interface have been systematically investigated by using nonequilibrium molecular dynamic simulations. The different types of single-vacancy and Stone–Wales defects were considered. The simulation results showed that the interfacial thermal conductance would decrease linearly with the increase of single-vacancy concentrations and it decreased with the existence of Stone–Wales defects, then reached a platform as concentration increased, the value of which was close to the interfacial thermal conductance of Gr/h-BN with the line defect formed by Stone–Wales defects. The analyses on the phonon vibration power spectra and the stress analysis indicated that the degradation in the in-plane modes accounted for the decrease caused by single-vacancy, while the stress concentration distribution and the ripple appeared near the interface dominated the degradation caused by Stone–Wales defects. Additionally, the effects of system dimensions and temperature on the interfacial thermal conductance were investigated.