Thermal Conductivity of Suspended Few-Layer MoS2

TL;DR

This study demonstrates in-situ measurement of thermal conductivity in suspended MoS2, showing it can be tuned from crystalline to amorphous states, with implications for thermoelectric and energy applications.

Contribution

First in-situ measurement of thermal conductivity in suspended MoS2, revealing continuous tuning from crystalline to amorphous states due to phonon-defect scattering.

Findings

Thermal conductivity can be continuously tuned in MoS2.

A sharp drop indicates a crystalline-amorphous transition.

Results inform thermal management in nanoscale devices.

Abstract

Modifying phonon thermal conductivity in nanomaterials is important not only for fundamental research but also for practical applications. However, the experiments on tailoring the thermal conductivity in nanoscale, especially in two-dimensional materials, are rare due to technical challenges. In this work, we demonstrate in-situ thermal conduction measurement of MoS2 and find that its thermal conductivity can be continuously tuned to a required value from crystalline to amorphous limits. The reduction of thermal conductivity is understood from phonon-defects scatterings that decrease the phonon transmission coefficient. Beyond a threshold, a sharp drop in thermal conductivity is observed, which is believed to be a crystalline-amorphous transition. Our method and results provide guidance for potential applications in thermoelectrics, photoelectronics, and energy harvesting where thermal management is critical with further integration and miniaturization.