Phonon thermal rectification in hybrid graphene-: a molecular dynamics simulation

Abstract

We apply the non-equilibrium molecular dynamics approach (NEMD) to study thermal rectification in a hybrid graphene-carbon nitride system () under a series of positive and negative temperature gradients. In this study, the effects of temperature difference, between two baths (ΔT), and sample size on thermal rectification are investigated. Our simulation results indicate positive correlation between thermal rectification and temperature difference for ΔT > 60 K, and high thermal rectification values, up to around 50% for ΔT = 100 K. Furthermore, this behavior remains practically consistent among different sample lengths. The underlying mechanism leading to a preferable direction for phonons is calculated using phonon density of states (DOS) on both sides of the interface, and the contributions of in-plane and out-of-plane phonon modes in total thermal rectification are also explored.