Metal-Silicene Interaction Studied by Scanning Tunneling Microscopy

Ag atoms have been deposited on 3x3 silicene and R3xR3 silicene films by molecular beam epitaxy method in ultrahigh vacuum. Using scanning tunneling microscopy and Raman spectroscopy, we found that Ag atoms do not form chemical bonds with both 3x3 silicene and R3xR3 silicene films,which is due to chemically inert surface of silicene. On 3x3 silicene films, Ag atoms mostly form into stable flat top Ag islands. In contrast, Ag atoms form nanoclusters and glide on silicene films, suggesting more inert nature. Raman spectroscopy suggests that there is more sp2 hybridization in R3xR3 than in R7xR7/3x3silicene films