Silicene Nanoribbons on Pb-Reconstructed Si(111) Surface

Abstract

We report on the initial stage of growing of silicon nanostructures on Pb-induced √ 3 × √ 3 and √ 3 × √ 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 √ 3 × √ 3 reconstruction. These findings are interpreted within the framework of silicene nanoribbons grown on a bare Si(111) surface.

Structural model of silicene-like nanoribbons on a Pb-reconstructed Si(111) surface

“…1 shows an example of such NRs as revealed by STM topography measurements. The NRs consist of Si atoms directly adsorbed on the Si(111) surface, as it was argued in [ 47 ], based on geometry considerations and STM measurements. It is also known, that Pb atoms strongly diffuse on Si substrates [ 53 – 54 ], so they can easily make room for growing Si NRs.…”

“…Next, the Si layer was deposited onto the sample held at 200 K within 20 min. Details of the preparation can be found in [ 47 ]. The presented nanoribbons were obtained by two-step annealing: first at room temperature for 1 h, and then by direct heating at around 400 K for 5 min.…”

“…We started from the thinnest Pb substrates, which are and reconstructions of Pb on Si(111). Our STM studies on the Pb-reconstructed Si(111) surface revealed that deposited Si atoms form wide nanoribbons [ 47 ]. The NRs, running in three high-symmetry directions of the Si(111) surface, are several nanometers long, 1.6 nm wide and show a local reconstruction.…”

“…The NRs, running in three high-symmetry directions of the Si(111) surface, are several nanometers long, 1.6 nm wide and show a local reconstruction. Although no details on the atomic structure existed, these nanostructures have been interpreted in terms of silicene-like nanoribbons grown on the bare Si(111) surface [ 47 ].…”

Evidence for Electronically Isolated Atomic Chains: Sb–Pb Structures on the Si(553) Surface

“…It has been reported that in the case of homoepitaxy of GaAs, the Pb layer acts as a surface agent, enhancing layer-by-layer growth . A similar effect was observed on the Cu − and Si(111) surfaces. , All of these studies, experimental as well as theoretical, were devoted to epitaxial growth on flat low-index surfaces.…”