Structure Determination of Multilayer Silicene Grown on Ag(111) Films by Electron Diffraction: Evidence for Ag Segregation at the Surface

The structure of multilayer silicene formed on Ag(111) films was studied by low-energy electron diffraction. It turned out that the experimental data cannot be explained by proposed models that only consider buckling of silicon atoms. We have rather found that multilayer silicene on Ag(111) is actually a thin film of bulklike silicon terminated with the Si(111)root 3 x root 3-Ag surface. The results are compared to previous works and clearly show the importance to properly understand the structure of the system when discussing its electronic properties.