Surface reconstruction induced geometries of Si clusters

TL;DR

This paper proposes models for intermediate-sized silicon clusters based on surface reconstruction principles, combining surface-like features with a bulk-like core, and analyzes their stability and electronic properties using first-principles calculations.

Contribution

It generalizes surface reconstruction arguments to model geometries of Si clusters of specific sizes, integrating surface and bulk features.

Findings

Models resemble stable Si surface reconstructions

First-principles calculations show favorable energetics

Electronic structure analysis provides insight into reactivity

Abstract

We discuss a generalization of the surface reconstruction arguments for the structure of intermediate size Si clusters, which leads to model geometries for the sizes 33, 39 (two isomers), 45 (two isomers), 49 (two isomers), 57 and 61 (two isomers). The common feature in all these models is a structure that closely resembles the most stable reconstruction of Si surfaces, surrounding a core of bulk-like tetrahedrally bonded atoms. We investigate the energetics and the electronic structure of these models through first-principles density functional theory calculations. These models may be useful in understanding experimental results on the reactivity of Si clusters and their shape as inferred from mobility measurements.