Heat dissipation in few-layer MoS2 and MoS2/hBN heterostructure

TL;DR

This study measures the thermal conductivity of MoS2 and MoS2/hBN heterostructures, revealing that hBN significantly enhances heat dissipation, which is promising for thermal management in MoS2-based devices.

Contribution

The paper provides direct measurements of thermal conductivity in MoS2/hBN heterostructures and demonstrates the significant thermal conductivity enhancement due to hBN layers.

Findings

MoS2 thermal conductivity ranges from 12 to 24 W/mK.

Heterostructure with hBN shows eight-fold increase in thermal conductivity.

High thermal interface conductance (~70 MW/m²K) between MoS2 and hBN.

Abstract

State-of-the-art fabrication and characterization techniques have been employed to measure the thermal conductivity of suspended, single-crystalline MoS2 and MoS2/hBN heterostructures. Two-laser Raman scattering thermometry was used combined with real time measurements of the absorbed laser power, which allowed us to determine the thermal conductivities without any assumptions. Measurements on MoS2 layers with thicknesses of 5 and 14 exhibit thermal conductivity in the range between 12 and 24 Wm-1K-1. Additionally, after determining the thermal conductivity of a selected MoS2 sample, an hBN flake was transferred onto it and the effective thermal conductivity of the heterostructure was subsequently measured. Remarkably, despite that the thickness of the hBN layer was less than a third of the thickness of the MoS2 layer, the heterostructure showed an almost eight-fold increase in the thermal conductivity, being able to dissipate more than 10 times the laser power without any visible sign of damage. These results are consistent with a high thermal interface conductance between MoS2 and hBN and an efficient in-plane heat spreading driven by hBN. Indeed, we estimate G 70 MWm-2K-1 which is significantly higher than previously reported values. Our work therefore demonstrates that the insertion of hBN layers in potential MoS2 based devices holds the promise for efficient thermal management.