Molecular Dynamics Simulations of Single-Layer Molybdenum Disulphide (MoS2): Stillinger-Weber Parametrization, Mechanical Properties, and Thermal Conductivity

摘要

We present a parameterization of the Stillinger-Weber potential to describethe interatomic interactions within single-layer MoS2 (SLMoS2). The potentialparameters are fitted to an experimentally-obtained phonon spectrum, and theresulting empirical potential provides a good description for the energy gapand the crossover in the phonon spectrum. Using this potential, we performclassical molecular dynamics simulations to study chirality, size, and straineffects on the Young's modulus and the thermal conductivity of SLMoS2. Wedemonstrate the importance of the free edges on the mechanical and thermalproperties of SLMoS2 nanoribbons. Specifically, while edge effects are found toreduce the Young's modulus of SLMoS2 nanoribbons, the free edges also reducethe thermal stability of SLMoS2 nanoribbons, which may induce melting wellbelow the bulk melt temperature. Finally, uniaxial strain is found toefficiently manipulate the thermal conductivity of infinite, periodic SLMoS2.