Phonon Thermal Properties of Transition-Metal Dichalcogenides MoS2 and MoSe2 Heterostructure

Two prototype transition-metal dichalcogenide (TMDC) materials, MoS 2 and MoSe 2, have attracted growing attention as promising 2D semiconductors. The heterostructure created by stacking the 2D monolayers in the out-of-plane direction exhibits peculiar properties that can be utilized in electronic applications. The lateral and flexural phonon transport behaviors in MoS 2 /MoSe 2 heterobilayer are comprehensively investigated using classical molecular dynamics simulations. In-plane thermal conductivity (κ) and out-of-plane interfacial thermal resistance ( R ) are calculated by nonequilibrium molecular dynamics (NEMD) and transient pump–probe methods, respectively. Thermal conductivity of MoS 2 /MoSe 2 bilayer 2D sheet is characterized as 28.8 W/m·K, which preserves the high thermal conductivity of most TMDC materials. The maximum κ reductions of MoS 2, MoSe 2, and heterobilayer amount to 83.0, 68.9, and 77.1%, respectively, with increasing temperatures from 100 to 500 K. It is also found that the basal-plane thermal performance of MoS 2 /MoSe 2 bilayer will not be affected by interfacial interactions, which is important in industrial applications. The predicted out-of-plane flexural phonon conductance results reveal that heat flux runs preferably from MoS 2 to MoSe 2 than in the reverse direction.