Thickness-dependence of the in-plane thermal conductivity and the interfacial thermal conductance of supported MoS2.

Abstract

Nowadays, experimental research advances in condensed matter physics are deep-rooted in the development and manipulation of nanomaterials, making it essential to explore the fundamental properties of materials that are candidates for nanotechnology. In this work, we study the dependence of the molybdenum disulfide (MoS2) Raman modes on the sample temperature and on the excitation laser power. From the correlation between these two sets of measurements, we determine the planar thermal conductivity of MoS₂monolayers, bilayers, trilayers, four layers, seven layers, and eight layers. We find a nonmonotonic behavior, with the thermal conductivity decreasing from 38 Wm-1K-1 to 24 Wm-1K-1, going from monolayer to trilayers, and then increasing from 24 Wm^-1K^-1to 50 Wm^-1K^-1when the thickness increases from three to eight layers. We associate this behavior with a convolution of two different phonon scattering processes: boundary scattering and interlayer scattering. We also report a monotonic thickness dependence of the interfacial thermal conductance of n-layers of MoS₂on SiO₂/Si, which ranges from 0.9 MWm^-2K^-1for a monolayer to 3.2 MWm^-2K^-1for eight layers films. .