Out-of-plane thermal conductivity of polycrystalline silicon nanofilm by molecular dynamics simulation

The out-of-plane thermal conductivity of polycrystalline silicon nanofilm is investigated by molecular dynamics simulation. The polycrystalline silicon nanofilm with a random shape of grains is generated by the three-dimensional Voronoi tessellation method. The out-of-plane thermal conductivity of polycrystalline silicon nanofilm at different temperature, film thickness, and average grain size is calculated by the Muller-Plathe method. The results indicate that the polycrystalline thermal conductivity is lower than that of the bulk single crystal and the single crystal nanofilm of silicon. The out-of-plane thermal conductivity of polycrystalline silicon nanofilm is insensitive to temperature and film thickness that is apparently larger than grain size, but mainly depends on the grain size.