  Understanding the physical processes involved in interfacial heat transfer is
critical for the interpretation of thermometric measurements and the
optimization of heat dissipation in nanoelectronic devices that are based on
transition metal dichalcogenide (TMD) semiconductors. We model the phononic and
electronic contributions to the thermal boundary conductance (TBC) variability
for the MoS$_{2}$-SiO$_{2}$ and WS$_{2}$-SiO$_{2}$ interface. A
phenomenological theory to model diffuse phonon transport at disordered
interfaces is introduced and yields $G$=13.5 and 12.4 MW/K/m$^{2}$ at 300 K for
the MoS$_{2}$-SiO$_{2}$ and WS$_{2}$-SiO$_{2} $ interface, respectively. We
compare its predictions to those of the coherent phonon model and find that the
former fits the MoS$_{2}$-SiO$_{2}$ data from experiments and simulations
significantly better. Our analysis suggests that heat dissipation at the
TMD-SiO$_{2}$ interface is dominated by phonons scattered diffusely by the
rough interface although the electronic TBC contribution can be significant
even at low electron densities ($n\leq10^{12}$ cm$^{-2}$) and may explain some
of the variation in the experimental TBC data from the literature. The physical
insights from our study can be useful for the development of thermally aware
designs in TMD-based nanoelectronics.
