Anisotropic GaAs island phase grown on flat GaP: spontaneously formed quantum wire array

TL;DR

This paper investigates the spontaneous formation of anisotropic GaAs quantum wire arrays on GaP, revealing unique island orientations driven by facet energy differences, which are not explained by existing models.

Contribution

It introduces observations of anisotropic GaAs islands on GaP and highlights the role of facet energy differences in their orientation, challenging current theoretical predictions.

Findings

GaAs wires form early during strained growth on GaP

Electron diffraction shows elongated, faceted islands without dislocations

Island orientation is influenced by facet energy differences, unlike in Ge/Si systems

Abstract

A dense phase of GaAs wires forms in the early stages of strained growth on GaP,assembling from elongated Stranski-Krastanow islands. The electron diffraction during growth is consistent with long, faceted GaAs islands that are anisotropically deformed without dislocations. The lateral wire period and long shapes are not predicted by published models, though we conclude that the island orientation is picked out by facet energy inequivalencies not present in the analogous system of Ge islands on Si.