Theoretical analysis of thermal boundary conductance of MoS2-SiO2 and WS2-SiO2 interface

TL;DR

This paper provides a theoretical analysis of the thermal boundary conductance at MoS2-SiO2 and WS2-SiO2 interfaces, highlighting the dominant phononic scattering mechanisms and electronic contributions relevant for nanoelectronic heat management.

Contribution

A phenomenological model for diffuse phonon transport at disordered interfaces is introduced, improving understanding of TBC variability in TMD-based interfaces.

Findings

Diffuse phonon scattering dominates heat dissipation at the interface.

The model predicts TBC values close to experimental data.

Electronic contributions to TBC can be significant at low electron densities.

Abstract

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.