Model reconstructions for the Si(337) orientation

TL;DR

This paper uses a genetic algorithm combined with empirical potentials and ab initio methods to explore and identify various reconstructions of the Si(337) surface, including known and novel structures.

Contribution

It introduces a comprehensive computational approach to model and analyze the Si(337) surface reconstructions, revealing new structures and validating previous models.

Findings

Recovered most known Si(337) reconstructions

Discovered new Si(337) surface structures

Validated models with ab initio relaxation

Abstract

Although unstable, the Si(337) orientation has been known to appear in diverse experimental situations such as the nanoscale faceting of Si(112), or in the case of miscutting a Si(113) surface. Various models for Si(337) have been proposed over time, which motivates a comprehensive study of the structure of this orientation. Such a study is undertaken in this article, where we report the results of a genetic algorithm optimization of the Si(337)-$(2\times 1)$ surface. The algorithm is coupled with a highly optimized empirical potential for silicon, which is used as an efficient way to build a set of possible Si(337) models; these structures are subsequently relaxed at the level of ab initio density functional methods. Using this procedure, we retrieve most of the (337) reconstructions proposed in previous works, as well as a number of novel ones.