Conducting boron sheets formed by the reconstruction of the \alpha-boron (111) surface

TL;DR

This study uses ab initio methods to predict novel boron surface reconstructions, revealing a planar boron sheet with conductive properties that could serve as a precursor for boron nanostructures.

Contribution

First application of ab initio structure prediction to oron (111) surface reconstructions, identifying a stable planar boron sheet with potential nanostructure applications.

Findings

Predicted a stable, conductive boron monolayer at the surface.

Identified new low-energy surface reconstruction geometries.

Isolated boron sheet is the ground state in vacuum at ta=1/5.

Abstract

Systematic ab initio structure prediction was applied for the first time to predict low energy surface reconstructions by employing the minima hopping method on the \alpha-boron (111) surface. Novel reconstruction geometries were identified and carefully characterized in terms of structural and electronic properties. Our calculations predict the formation of a planar, mono-layer sheet at the surface, which is responsible for conductive surface states. Furthermore, the isolated boron sheet is shown to be the ground state 2D-structure in vacuum at a hole density of \eta=1/5 and is therefore a potential candidate as a precursor for boron nano-structures.