Phonon transport in single-layer Mo1-xWxS2 alloy embedded with WS2 nanodomains

TL;DR

This paper demonstrates that alloying and nanodomain embedding significantly reduce the thermal conductivity of 2D MoS2 by enhancing phonon scattering, with potential applications in thermoelectrics and thermal management.

Contribution

It introduces a novel combined alloying and nanodomain strategy to effectively suppress thermal conductivity in 2D materials, supported by first-principles calculations.

Findings

Thermal conductivity of MoS2 can be reduced to less than 10% of its original value.

Both high- and low-frequency phonons are strongly scattered by alloying and nanodomains.

The approach provides a pathway for tuning thermal properties of 2D materials.

Abstract

Two-dimensional (2-D) transition metal dichalcogenides (TMDs) have shown numerous interesting physical and chemical properties, making them promising materials for electronic, optoelectronic, and energy applications. Tuning thermal conductivity of two-dimensional (2-D) materials could expand their applicability in many of these fields. In this paper, we propose a strategy of using alloying and nanodomains to suppress the thermal conductivity of 2-D materials. To predict the thermal conductivity of 2-D alloy embedded with nanodomains, we employ the Green's function approach to assess the phonon scattering strength due to alloying and nanodomain embedding. Our first-principles-driven phonon Boltzmann transport equation calculations show that the thermal conductivity of single-layer MoS2 can be reduced to less than one-tenth of its intrinsic thermal conductivity after alloying with W and introducing nanodomains due to the strong scattering for both high- and low-frequency phonons. The strategies to further reduce the thermal conductivity are also discussed.