Graphene is a promising material to design faster microprocessors given its exceptionally high thermal conductivity. However, due to its null electronic band gap, graphene must be combined with high-electric conductivity materials such as boron nitride to manufacture competitive alternatives to traditional semiconductors. Thus, the goal of this study is to determine the thermal conductivities and heat capacities of two-dimensional superlattices of graphene and boron nitride as a function of the secondary periodicity and interface orientation. We apply the Green-Kubo method to atomic trajectories calculated with Molecular Dynamics to determine the thermal conductivities of superlattices with periodicities between one and five in the armchair and zigzag orientations at 300 K. Results show that conductivities increase with decreasing periodicity, in good agreement with predictions made with Harmonic Lattice Dynamics. Thermal conductivities parallel to the interface are significantly higher than those perpendicular to the interface in the armchair configuration and vice versa in the zigzag orientation. Moreover, the heat capacities are practically independent of the periodicity and interface orientation up to 1500 K.
Evidence of direct electronic band gap in two-dimensional van der Waals indium selenide crystals