Metal-silicene interaction studied by scanning tunneling microscopy

Ag atoms have been deposited on 3 x 3 silicene and √3 x √3 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 3 x 3 silicene and √3 x √3 silicene films, which is due to the chemically inert surface of silicene. On 3 x 3 silicene films, Ag atoms mostly form into stable flat-top Ag islands. In contrast, Ag atoms form nanoclusters and glide on silicene films, suggesting a more inert nature. Raman spectroscopy suggests that there is more sp 2 hybridization in √3 x √3 than in √7 x √7/3 x 3 silicene films.