Thermal Boundary Conductance of Two-Dimensional $MoS_{2}$ Interfaces

TL;DR

This study uses molecular dynamics simulations to evaluate the thermal boundary conductance of MoS2 interfaces, revealing how it varies with material interactions, layer number, and temperature, which is crucial for thermal management in 2D devices.

Contribution

It provides new insights into how the thermal boundary conductance of MoS2 interfaces can be tuned by interface strength, layer number, and substrate matching, supported by simulation data.

Findings

TBC of 2D MoS2 interfaces is generally low, below ~20 MW/m^2K.

TBC increases with van der Waals coupling strength, temperature, and number of layers.

TBC can be modulated by interface interaction, layer number, and substrate phonon density of states.

Abstract

Understanding the thermal properties of two-dimensional (2D) materials and devices is essential for thermal management of 2D applications. Here we perform molecular dynamics simulations to evaluate both the specific heat of $MoS_{2}$ as well as the thermal boundary conductance (TBC) between one to five layers of $MoS_{2}$ with amorphous $SiO_{2}$ and between single-layer $MoS_{2}$ and crystalline $AlN$. The results of all calculations are compared to existing experimental data. In general, the TBC of such 2D interfaces is low, below ~20 $MWm^{-2}K^{-1}$, due to the weak van der Waals (vdW) coupling and mismatch of phonon density of states (PDOS) between materials. However, the TBC increases with vdW coupling strength, with temperature, and with the number of $MoS_{2}$ layers (which introduce additional phonon modes). These findings suggest that the TBC of 2D materials is tunable by modulating their interface interaction, the number of layers, and finding a PDOS-matched substrate, with important implications for future energy-efficient 2D electronics, photonics, and thermoelectrics.