Phonon Thermal Properties of Heterobilayers with a Molecular Dynamics Study

Two-dimensional transition metal dichalcogenide materials, such as the heterobilayers by piling up the monolayers in out-of-plane direction, behave unique performances in applications of nanoelectronic components. In this work, the in-plane thermal conductivities of MoS₂–MoSe₂, MoS₂–WS₂, and MoS₂–WSe₂ heterobilayers are investigated with nonequilibrium molecular dynamics method by considering the effects of system dimensions, temperature, coupling strength, strain, and misorientation. The results show that the thermal conductivity decreases as the temperature rises from 100 K to 500 K. The effect of coupling strength on the thermal conductivity is not significant. Both strain and misorientation could result in a reduction in the thermal conductivity, and the effect of tensile strain is stronger than that of compressive strain. An analysis based on phonon spectral energy density is performed to further understand phonon thermal properties in heterobilayers. This work provides a fundamental basis for regulating thermal transport in two-dimensional heterobilayer-based nanoelectronics.