Heat dissipation in few-layer MoS2and MoS2/hBN heterostructure

State-of-the-art fabrication and characterisation 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. Measurements on MoS2 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 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 hal 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 ten times the laser power without any visible sign of damage. These results are consistent with a high thermal interface conductance G between MoS2 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 MoS2-based devices holds the promise for efficient thermal management.This work was partially funded by the European Union under the H2020 FET-OPEN NANOPOLY (GA 289061) and Spanish Ministry of Science projects SIP (PGC2018-101743-B-I00), ADAGIO (PGC2018-094490-B-C22), 2DTecBio (FIS2017-85787-R) and 2DENGINE (PID2019-111773RB- I00/AEI/10.13039/501100011033). E D C acknowledges the Spanish Ministry of Science for the Juan de la Cierva Fellowship (JC-2015-25201) and the Ramon y Cajal fellowship (RYC2019-027879-I). D N U and J F S acknowledge the Ramón y Cajal fellowships RYC2014-15392 and RYC2019-028368-I/AEI/10.13039/501100011033. M V C acknowledges project (Reference No. 103739) funded by the Agencia Estatal de Investigación through the PCI 2019 call. The Catalan Institute of Nanoscience and Nanotechnology (ICN2) is funded by the CERCA program/Generalitat de Catalunya, and is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706). K W and T T acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan (Grant Number JPMXP0112101001) and JSPS KAKENHI (Grant Numbers 19H05790 and JP20H00354)