  We report experimental and computational studies of thermal transport
properties in hexagonal boron nitride (hBN) encapsulated molybdenum disulfide
(MoS2) structure using refined optothermal Raman techniques, and reveal very
high interfacial thermal conductance between hBN and MoS2. By studying the
Raman shift of hBN and MoS2 in suspended and substrate-supported thin films
under varying laser power and temperature, we calibrate lateral (in-plane)
thermal conductivity of hBN and MoS2 and the vertical interfacial thermal
conductance in the hBN/MoS2/hBN heterostructure as well as the interfaces
between heterostructure and substrate. Crucially, we have found that
interfacial thermal conductance between hBN and encapsulated MoS2 is 74MW/m2K
and 72MW/m2K in supported and suspended films, respectively, which are
significantly higher than interfacial thermal conductance between MoS2 and
other substrates. Molecular dynamics (MD) computations conducted in parallel
have shown consistent results. This work provides clear evidence of
significantly efficient heat dissipation in hBN/MoS2/hBN heterostructures and
sheds light on building novel hBN encapsulated nanoelectronics with efficient
thermal management.
