Vacancy-defect-induced diminution of thermal conductivity in silicene

Using equilibrium molecular dynamic simulations, we calculate the phonon thermal conductivity of a graphene-like silicon nanosheet called silicene at room temperature. We find that the in-plane thermal conductivity of silicene sheets is about one order of magnitude lower than that of bulk silicon. We further investigate the effects of vacancy defects on thermal conductivity and observe its significant diminution owing to the effect of phonon-defect scattering. Our results show that phonon transport in a silicene sheet is strongly affected by vacancy concentration, vacancy size, and vacancy boundary shape; this could be used to guide defects engineering of the thermal properties of low-dimensional silicon materials. © Copyright EPLA, 2012.