Understanding thermal transport properties of Transition Metal Dichalcogenides

2D-bonded Transition Metal Dichalcogenides (TMDs) have received significant attention in the past years because of their peculiar properties that differ from 3D-bonded materials. Reaching an understanding of thermal properties is crucial for many application fields, such as electronics and thermoelectrics. We present a theoretical study of the phonon heat transport properties of bulk and monolayer WS2, WSe2, MoS2 and MoSe2, focusing on the microscopic origins giving rise to the macroscopic thermal conductivity. We calculate the thermal conductivity of TMDs by solving the full Boltzmann Transport Equation for phonons. We perform first principles calculations with SIESTA based on Density Functional Theory and the Temperature Dependent Effective Potential package for finite temperature lattice dynamics calculations. By employing this method we compute the thermal properties for the TMDs at room temperature and we compare the results with experiments on a full range of thicknesses, which demonstrates the reliability and efficiency of our computational method. We compare the results for different TMDs and reach a unifying picture of heat transport in 2D-bonded semiconductors, which will be useful for future technologies.