Silicene versus two-dimensional ordered silicide: Atomic and electronic structure of Si- (19 × 19)R23.4°/Pt(111)

Abstract

We discuss the possibility of a two-dimensional ordered structure formed upon deposition of Si on metal surfaces. We investigate the atomic and electronic structure of the Si-(19×19)R23.4°/Pt(111) surface reconstruction by means of a set of experimental surface-science techniques supported by theoretical calculations. The theory achieves very good agreement with the experimental results and is corroborating beyond any doubt that this phase is a surface alloy consisting of Si3Pt tetramers that resembles a twisted kagome lattice. These findings render unlikely any formation of silicene or germanene on Pt(111) and other transition-metal surfaces.