Structure of incommensurate gold sulfide monolayer on Au(111)

Abstract

Two-dimensional confined systems, such as substrate-supported incommensurate layers, are of interest because their structural and electronic properties may differ from those of bulk materials. While advances in experimental techniques have resulted in the growth of many such interesting systems, progress can often be hampered by the lack of an atomistic-scale understanding of the structure, especially for incommensurate systems. In this work, we develop an atomic-scale model for an ordered incommensurate gold-sulfide (AuS) adlayer that has been previously demonstrated to exist on the Au(111) surface, following sulfur deposition and annealing to 450 K. We introduce theoretical techniques within density functional theory to take into account charge transfer in an incommensurate system and model scanning tunneling microscopy images, which are in good agreement with experiment. Our simulations indicate that this model is remarkably robust. We analyze the nature of bonding in this structure using state-of-the-art Wannierfunction based techniques. Our analysis provides a natural explanation for the extraordinary robustness and unusual stoichometry of this layer. This structure and its chemistry have implications for related S-Au interfaces, such as those in self-assembled monolayers of thiols on Au substrates.3 Main text

The intriguing reaction of aromatic sulfonyl phthalimides with gold surfaces

“…25 An important issue of long standing discussion in the literature has been the debate about the nature of the rectangular structures. 25,[27][28][29][30][34][35][36][37] Fig. 6 presents consecutive, unfiltered STM images at a scan size of 30 Â 30 nm 2 , illustrating the dynamic nature of the modified surface using p-fluorobenzenesulfonyl phthalimide.…”

“…On one side, the formation of a complex 2D AuS phase has been suggested for the rectangular structures. 25,[34][35][36][37] A model for this phase has been proposed on the basis of STM, Auger electron spectroscopy and density functional theory calculations. 38 On the other side, the behaviour of the rectangles has been attributed to chemisorbed sulfur adlayers.…”

Theoretical chemistry of gold. III

“…In addition to thiolates, a gold sulfide layer can exist on gold. Such an iccommensurate AuS layer on Au (111) was modelled by Quek et al 350 The structure shows up familiar tetracoordinate Au(III) and two-coordinate Au(I) moieties, the latter paired to Au-Au-bonded dimers.…”

Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

“…Nevertheless, theoretical studies of rectangles formation have been less numerous than the experimental ones; two relevant works have been carried out. The first one, 13 which is based on the experimental results of Biener et al, 5 uses the density functional theory (DFT) at the PW91 level 14 to propose a 2D Au-S phase with 1:1 stoichiometry. The periodicity of this phase is described by an incommensurate supercell whose dimensions are consistent with the experimental measures.…”