Temperature profiles and thermal conductivities of nanostructured transition metal dichalcogenides

Thermal transport in nanostructured transition metal dichalcogenides has been examined using molecular dynamics simulations. The study is focused on the calculation of the thermal conductivities of pristine and periodically patterned MX2 crystals, assessing the effects of patterning these materials with stripes of substitutional defects. The influence of several patterning parameters has been examined, such as the number and the width of defect stripes and the separation distance between consecutive stripes. The effect of a single defect stripe is also discussed for different compositions of the MX2 crystals and atomic types of substitutional defects. The thermal conductivity of pristine MX2 materials is reversely related to the width of the phononic band gap. Nanostructured materials with stripes of substitutional defects exhibit discontinuous temperature profiles with step-like characteristics, whilst the effect becomes weaker with increasing defect density. The thermal conductivity of periodically patterned crystals is much lower than the one of the pristine materials and increases by increasing the number of defect stripes. (C) 2019 Elsevier Ltd. All rights reserved.