Interfacial thermal conductance of BP/MoS2 van der Waals heterostructures: An insight from the phonon transport

Abstract

Recently, two-dimensional (2D) van der Waals (vdW) heterostructures have attracted a great deal of attention due to their outstanding properties and are considered an alternative for the next generation of microelectronic devices. The interfacial thermal transport properties of these heterostructures are of great importance for their practical applications. Herein, we investigate the effect of temperature and three different vacancy defects on the interfacial thermal conductance (ITC) of BP/MoS2 vdW heterostructures by using molecular dynamics. The results show that its ITC increases by 167% when the temperature increases from 100 to 350 K. In addition, a strong dependence of the ITC on the concentration of the Mo vacancy defects is also found. In this study, phonon dispersion relations, phonon density of states, and phonon participation rates are used to analyze the physical mechanisms of interfacial thermal transport behavior. Interestingly, the Mo vacancy defects will cause the phonon density of states to shift towards lower frequencies, and the number of low-frequency phonons will increase with increasing defect concentration. In particular, the Mo vacancy defects will lead to phonon non-localization features in the low-frequency range of 4–6 THz, which is significantly different from the phonon participation rate of the system with the introduction of the S vacancy defects and the double S vacancy defects. These findings could provide theoretical support for thermal conductance manipulation of devices based on BP/MoS2 vdW heterostructures.