Measurement of lateral and interfacial thermal conductivity of single- and bi-layer MoS2 and MoSe2 using refined optothermal Raman technique

Abstract

Atomically thin materials such as graphene and semiconducting transition metal dichalcogenides (TMDCs) have attracted extensive interest in recent years, motivating investigation into multiple properties. In this work, we demonstrate a refined version of the optothermal Raman technique to measure the thermal transport properties of two TMDC materials, MoS2 and MoSe2, in single-layer (1L) and bi-layer (2L) forms. This new version incorporates two crucial improvements over previous implementations. First, we utilize more direct measurements of the optical absorption of the suspended samples under study and find values ~40% lower than previously assumed. Second, by comparing the response of fully supported and suspended samples using different laser spot sizes, we are able to independently measure the interfacial thermal conductance to the substrate and the lateral thermal conductivity of the supported and suspended materials. The approach is validated by examining the response of a suspended film illuminated in different radial positions. For 1L MoS2 and MoSe2, the room-temperature thermal conductivities are (84+/-17) W/mK and (59+/-18) W/mK, respectively. For 2L MoS2 and MoSe2, we obtain values of (77+/-25) W/mK and (42+/-13) W/mK. Crucially, the interfacial thermal conductance is found to be of order 0.1-1 MW/m2K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.

References in corpus (9)

• Electric Field Effect in Atomically Thin Carbon Films
• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Atomically thin MoS2: A new direct-gap semiconductor
• Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Emerging Device Applications for Semiconducting Two-Dimensional Transition Metal Dichalcogenides
• Mobility engineering and metal-insulator transition in monolayer MoS2
• Dimensional crossover of thermal transport in few-layer graphene materials
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2

Cited by in corpus (9)

• Temperature Dependent Thermal Boundary Conductance of Monolayer MoS${}_2$ by Raman Thermometry
• How to Characterize Thermal Transport Capability of 2D Materials Fairly? - Sheet Thermal Conductance and the Choice of Thickness
• Phonon and Thermal Properties of Quasi-Two-Dimensional FePS3 and MnPS3 Antiferromagnetic Semiconductor Materials
• Reduced Thermal Conductivity of Supported and Encased Monolayer and Bilayer MoS${}_2$
• Tunable exciton-optomechanical coupling in suspended monolayer MoSe2
• Hexagonal Boron Nitride-Graphene Heterostructures with Enhanced Interfacial Thermal Conductance for Thermal Management Applications
• Achieving huge thermal conductance of metallic nitride on graphene through enhanced elastic and inelastic phonon transmission
• Direct Visualization of Electric Field induced Structural Dynamics in Monolayer Transition Metal Dichalcogenides
• Simultaneous measurement of anisotropic thermal conductivity and thermal boundary conductance of 2-dimensional materials