An Array of Layers in Silicon Sulfides: Chain-like and Ground State Structures

TL;DR

This paper explores the stable, anisotropic ground state structures of silicon monosulfide monolayers, revealing the role of Si-S double chains and d orbital hybridization, expanding the potential for silicon-sulfide nanostructures.

Contribution

It introduces a new set of anisotropic silicon monosulfide structures with enhanced stability due to Si-S double chains and d orbital hybridization, expanding silicon-sulfide nanostructure possibilities.

Findings

Identification of stable anisotropic silicon monosulfide structures

Role of Si-S double chains in structural stability

Involvement of d orbitals in hybridization

Abstract

While much is known about isoelectronic materials related to carbon nanostructures, such as boron nitride layers and nanotubes, rather less is known about equivalent silicon based materials. Following the recent discovery of phosphorene, we herein discuss isoelectronic silicon monosulfide monolayers. We describe a set of anisotropic ground state structures that clearly have a high stability with respect to the near isotropic silicon monosulfide monolayers. The source of the layer anisotropy is related to the presence of Si-S double chains linked by some Si-Si covalent bonds, which lye at the core of the increased stability, together with a remarkable spd hybridization on Si. The involvement of d orbitals brings more variety to silicon-sulfide based nanostructures that are isoelectronic to phosphorene, which could be relevant for future applications, adding extra degrees of freedom.