Thermal transport properties of monolayer MoSe2 with defects

Abstract

Two-dimensional (2D) molybdenum diselenide (MoSe₂) as one of the ultrathin transition metal dichalcogenides (TMDs) has attracted considerable attention because of its potential applications in thermoelectric and nano-electronic devices. Here, the thermal conductivity of monolayer MoSe₂ and its responses to simulated size and defects are studied by nonequilibrium molecular dynamics simulations. With the increase of sample length, the thermal conductivity of monolayer MoSe₂ nanoribbons exhibits an enhancement whereas it is insensitive to the width. At room temperature, the thermal conductivities of monolayer MoSe₂ along armchair and zigzag directions are 17.758 and 18.932 W (m K)⁻¹, respectively, which are consistent with previous results. The impact of defects on thermal conductivity has also been studied by varying the concentration of the vacancy from 0.1% to 0.5%. The results show that an increase of the defect concentration will greatly suppress the thermal conductivity. The 0.5% defect concentration with a Mo vacancy can result in a thermal conductivity reduction of ∼43%. Such a study would provide a good insight into the tunable thermal transport for potential applications of not only monolayer MoSe₂, but also many other TMDs.