  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.
