Computational study of the properties of silicon thin films on graphite

Resumo

The behavior of two thin silicon films on a surface of perfect graphite is studied by means of molecular dynamics. One film is a five-layer section of Si(001) crystal, while the other is a double layer of silicene. The structure of Si films of graphite is studied by plotting Voronoi polyhedra with the exclusion of small geometric elements, and by calculating the function of radial distribution. The Si(001) film on graphite has greater sustainability than the double layer of silicene. Both the Si(001) film with diamond-like structure and the silicene film are transformed slightly in horizontal directions; in the latter case, mainly the bottom layer is distorted. Increasing the vertical displacements of atoms in the silicene resulted in strong cohesion of its layers and greater roughness. However, the positioning of the double layer of silicene on graphite is more energetically favorable than that of the Si(001) film on the graphite substrate.