Temperature-dependent nonlinear phonon shifts in a supported MoS2 monolayer

TL;DR

This study investigates how temperature affects nonlinear phonon shifts in a supported MoS2 monolayer using Raman spectroscopy, revealing insights into thermal properties relevant for nanoelectronic applications.

Contribution

It provides the first detailed analysis of nonlinear temperature dependence of Raman modes in supported MoS2 and links phonon behavior to thermal management in 2D materials.

Findings

Raman modes exhibit nonlinear temperature dependence.

Phonon shifts explained by optical phonon decay into acoustic phonons.

Derived local temperature changes under laser heating.

Abstract

We report Raman spectra measurements on a MoS2 monolayer supported on SiO2 as a function of temperature. Unlike in previous studies, the positions of the two main Raman modes, E2g1 and A1g exhibited nonlinear temperature dependence. Temperature dependence of phonon shifts and widths is explained by optical phonon decay process into two acoustic phonons. On the basis of Raman measurements, local temperature change under laser heating power at different global temperatures is derived. Obtained results contribute to our understanding of the thermal properties of two-dimensional atomic crystals and can help to solve the problem of heat dissipation, which is crucial for use in the next generation of nanoelectronic devices.