Heat dissipation in few-layer MoS ₂ and MoS ₂ /hBN heterostructure

Abstract

Abstract State-of-the-art fabrication and characterisation techniques have been employed to measure the thermal conductivity of suspended, single-crystalline MoS 2 and MoS 2 /hBN heterostructures. Two-laser Raman scattering thermometry was used combined with real time measurements of the absorbed laser power. Measurements on MoS 2 layers with thicknesses of 5 and 14 nm exhibit thermal conductivity in the range between 12 Wm −1 K −1 and 24 Wm −1 K −1 . Additionally, after determining the thermal conductivity of the latter MoS 2 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 hal of the thickness of the MoS 2 layer, the heterostructure showed an almost eight-fold increase in the thermal conductivity, being able to dissipate more than ten times the laser power without any visible sign of damage. These results are consistent with a high thermal interface conductance G between MoS 2 and hBN and an efficient in-plane heat spreading driven by hBN. Indeed, we estimate G ∼ 70 MW m −2 K −1 for hBN layer thermal conductivity of 450 Wm −1 K −1 which is significantly higher than previously reported values. Our work therefore demonstrates that the insertion of hBN layers in potential MoS 2 -based devices holds the promise for efficient thermal management.