Nanoscale investigation of Si nanoribbon growth on Ag(110)

Abstract

We present a nanoscale investigation by means of scanning tunneling microscopy of Si nanostructure growth on the anisotropic silver (110) surface, in the submonolayer range. Four types of Si nanostructures are studied statistically as a function of the substrate temperature in the range 300 K to 500 K: isolated single-and double nanoribbons, which differ only by a factor of two in their width, and their respective bi-dimensional counterparts in the self-assembly regime. Our observations highlight different growth regimes controlled by kinetics. Below 320 K, the Si adatoms diffuse along the easy [11 0] direction, forming essentially isolated single nanoribbons randomly distributed on the silver terraces. At higher temperatures, transverse diffusion along the [001] direction is activated and a competition between the growth of self-assembled single nanoribbons and isolated double nanoribbons is observed. Above 440 K, a transition from one-to two-dimensional double nanoribbon growth is evidenced. At 490 K, the Si deposition results in the formation of massively self-assembled double nanoribbons. Based on Arrhenius analyses, activation barriers are found to be (125 + 15) meV and (210 + 20) meV for the formation of isolated Si nanoribbons and self-assembled Si double nanoribbons, respectively. Our results allow for a better understanding of the kinetic limiting processes which determine the submonolayer morphology and illustrate the role played by the missing row reconstruction of the Ag(110) surface in the formation of extended Si nanoribbon arrays.

Epitaxial growth and structural properties of silicene and other 2D allotropes of Si

“…The (5 × 2) superstructure was found to be stable until 490 K, temperature above which a silver surface faceting induced by Si adatoms occurs. 106,107 Honeycomb models. Elucidating the atomic structure of Si NRs has given rise to a long debate.…”

“…The (5 × 2) superstructure was found to be stable until 490 K, temperature above which a silver surface faceting induced by Si adatoms occurs. 106,107…”

“…In 2018, Daher Mansour et al gave a deeper insight in the growth mechanisms of Si NRs on Ag (110). 106 Their nanoscale investigation by means of STM for substrate temperature ranging from 300 K to 500 K showed the formation of local (3 × 2) superstructures composed of SNRs between 390 and 440 K and extended (5 × 2) superstructures above 440 K. This study outlines the role played by the MR reconstruction of the Ag (110) surface in the formation of extended Si NR arrays.…”

Magnetic anisotropy of one-dimensional Co nanostructures

“…Prior to Co deposition, the Ag(110) surface was firstly nanopatterned with a Si atomic layer, widely described in the literature (see for instance [20] and references therein, [21]). This nanotemplate consists in a Si NR array with a pitch of  2 nm, formed during Si deposition at 490 K onto the bare Ag(110) surface.…”

“…In this description, Si NRs of the 52 superstructure correspond to twin Si pentamer chains and will be denoted hereafter as double nanoribbons (DNRs). The Si NR array is stable until 490 K [21], temperature above which a silver surface faceting induced by Si adatoms occurs [23].…”