Conformal interface of monolayer molybdenum diselenide/disulfide and dielectric substrate with improved thermal dissipation

In recent years, the requirement for high-performance and lower-energy-consuming nano/micro devices has triggered widespread studies in low-dimensional materials with better interfacial thermal conduction. Here, we report the interfacial thermal resistance between single-layer transition metal dichalcogenides (MoX₂ (X = S or Se)) and their dielectric substrate, combining the differential 3ω method and finite element simulation. The MoX₂ samples are directly grown on SiO₂ substrate by chemical vapor deposition (CVD) to reduce interfacial thermal resistance due to conformal interface between MoX₂ and the substrate. We observe that the interfacial thermal resistance of MoS₂/oxide and MoSe₂/oxide reaches ∼4.76 × 10^-8 m² KW^-1 and ∼4.95 × 10^-7 m² KW^-1, one order of magnitude smaller than that in CVD-transferred or Scotch-tape samples, due to better interface with fewer voids and less roughness. The larger interfacial thermal resistance in MoSe₂ than in MoS₂ is believed to result from larger mismatch of atomic mass on the two sides of the interface. Our results indicate that the interfacial thermal resistance can be managed by improving the combination between MoX₂ and its dielectric substrate to enhance the thermal transport across their interface.