Silicene Nanoribbons on Pb-Reconstructed Si(111) Surface

We report on the initial stage of growing of silicon nanostructures on Pb-induced root 3 x root 3 and root 3 x root 7 reconstructed Si(111) surfaces. The deposition of 0.75 monolayer of Si at a temperature of around 200 K results in Si nanoribbons a few-nanometers in length running in three equivalent high symmetry directions of Si(111) surface, as revealed by low temperature scanning tunneling microscopy measurements. The nanoribbons are predominantly 1.6 nm wide and show local root 3 x root 3 reconstruction. These findings are interpreted within the framework of silicene nanoribbons grown on a bare Si(111) surface.