A comprehensive study of the (2R3x2R3)R30 structure of silicene on Ag(111)

TL;DR

This study re-analyzes experimental data to propose a new atomic model for silicene on Ag(111), explaining observed superstructures, disorder, and Moire patterns through a periodic arrangement of perfect and defective regions.

Contribution

It introduces a novel atomic model of silicene on Ag(111) based on detailed analysis, accounting for experimental observations and topological disorder effects.

Findings

Proposes a new atomic model for silicene structure.

Explains experimental superstructures and disorder.

Accounts for Moire patterns and apparent disorder.

Abstract

The deposition of one silicon monolayer on Ag(111) gives rise to a set of superstructures depending on growth conditions. These superstructures are correlated to the epitaxy between the honeycomb structure of silicon (so called silicene) and the silver substrate. In this paper, from a detailed re-analysis of experimental results, obtained by Scanning Tunneling Microscopy and by Low Energy Electron Diffraction on the (2R3x2R3)R30 structure, we propose a new atomic model of the silicene layer based on periodic arrangements of perfect areas of (2R3x2R3)R30 surrounded by defect areas. A generalization of this model explains the main experimental observations: deviation of the average direction, Moire patterns and apparent global disorder. In the frame of the proposed model, the apparent disorders observed on the STM images, would be topological effects, i.e. the silicene would keep a quasi-perfect honeycomb structure.