Germanium Adsorption On Ag(111): An Aes-Leed And Stm Study

The adsorption of germanium on Ag(111) has been investigated using Scanning Tunneling Microscopy, Auger Electron Spectroscopy and Low Energy Electron Diffraction. From the shape of the Auger peak-to-peak versus time curves, we deduce that at room temperature the growth mode is nearly layer-by-layer at least for the first two layers. In the sub-monolayer range, the growth starts by the formation of a (√ 3× √3)R30° surface superstructure which is complete at 1/3 monolayer coverage. Beyond this coverage a rectangular c(√3 × 7) superstructure is observed. STM images reveal that this last reconstruction is formed by an ordered arrangement of self-assembled Ge tetramers giving rise to a surprising undulation of the surface. Copyright © 2007 American Scientific Publishers All rights reserved

Thermal Stability Of Standalone Silicene Sheet

Extensive Monte Carlo simulations are carried out to study thermal stability of an infinite standalone silicon sheet. We used the Tersoff potential that has been used with success for silicon at low temperatures. However, the melting temperature Tm calculated with the original parameters provided by Tersoff is too high with respect to the experimental one. Agrawal, Raff and Komanduri have proposed a modified set of parameters to reduce T m. For comparison, we have used these two sets of parameters to study the stability and the melting of a standalone 2D sheet of silicon called silicene, by analogy with graphene for the carbon sheet. We find that 2D crystalline silicene is stable up to a high temperature unlike in 2D systems with isotropic potentials such as Lennard-Jones. The differences in the obtained results using two sets of parameters are striking. © Published under licence by IOP Publishing Ltd

A review on silicene - New candidate for electronics

Silicene–the silicon-based counterpart of graphene–has a two dimensional structure that is responsible for the variety of potentially useful chemical and physical properties. The existence of silicene has been achieved recently owing to experiments involving epitaxial growth of silicon as stripes on Ag(001), ribbons on Ag(110), and sheets on Ag(111). The nano-ribbons observed on Ag(110) were found–by both high definition experimental scanning tunneling microscopy images and density functional theory calculations–to consist of an arched honeycomb structure. Angle resolved photo-emission experiments on these silicene nano-ribbons on Ag(110), along the direction of the ribbons, showed a band structure which is analogous to the Dirac cones of graphene. Unlike silicon surfaces, which are highly reactive to oxygen, the silicene nano-ribbons were found to be resistant to oxygen reactivity.On the theoretical side, recent extensive efforts have been deployed to understand the properties of standalone silicene sheets and nano-ribbons using both tight-binding and density functional theory calculations. Unlike graphene it is demonstrated that silicene sheets are stable only if a small buckling (0.44 Å) is present. The electronic properties of silicene nano-ribbons and silicene sheets were found to resemble those of graphene.Although this is a fairly new avenue, the already obtained outcome from these important first steps in understanding silicene showed promising features that could give a new future to silicon in the electronics industry, thus opening a promising route toward wide-range applications. In this review, we plan to introduce silicene by presenting the available experimental and theoretical studies performed to date, and suggest future directions to be explored to make the synthesis of silicene a viable one

Physics And Chemistry Of Silicene Nano-Ribbons

We review our recent discovery of silicene in the form of silicon nano-ribbons epitaxially grown on silver (1 1 0) or (1 0 0) surfaces, which paves the way for the growth of graphene-like sheets. We further draw some perspectives for this unique novel material upon mild hydrogenation. © 2009 Elsevier B.V

Growth and dissolution kinetics of Au/Pb(1 1 1): an AES-LEED study

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Physics of silicene stripes

Silicene, a monolayer of silicon atoms tightly packed into a two-dimensional honeycomb lattice, is the challenging hypothetical reflection in the silicon realm of graphene, a one-atom thick graphite sheet, presently the hottest material in condensed matter physics. If existing, it would also reveal a cornucopia of new physics and potential applications. Here, we reveal the epitaxial growth of silicene stripes self-aligned in a massively parallel array on the anisotropic silver (110) surface. This crucial step in the silicene gold rush could give a new kick to silicon on the electronics road-map and opens the most promising route towards wide-ranging applications. A hint of superconductivity in these silicene stripes poses intriguing questions related to the delicate interplay between paired correlated fermions, massless Dirac fermions and bosonic quasi-particules in low dimensions