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Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires

III–V nanowires grown by the vapor–liquid–solid method often show self-regulated oscillations of group V concentration in a catalyst droplet over the monolayer growth cycle. We investigate theoretically how this effect influences the electron-to-hole ratio in Si-doped GaAs nanowires. Several factors...

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Autores principales: Dubrovskii, Vladimir G., Hijazi, Hadi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7712332/
https://www.ncbi.nlm.nih.gov/pubmed/32349326
http://dx.doi.org/10.3390/nano10050833
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author Dubrovskii, Vladimir G.
Hijazi, Hadi
author_facet Dubrovskii, Vladimir G.
Hijazi, Hadi
author_sort Dubrovskii, Vladimir G.
collection PubMed
description III–V nanowires grown by the vapor–liquid–solid method often show self-regulated oscillations of group V concentration in a catalyst droplet over the monolayer growth cycle. We investigate theoretically how this effect influences the electron-to-hole ratio in Si-doped GaAs nanowires. Several factors influencing the As depletion in the vapor–liquid–solid nanowire growth are considered, including the time-scale separation between the steps of island growth and refill, the “stopping effect” at very low As concentrations, and the maximum As concentration at nucleation and desorption. It is shown that the As depletion effect is stronger for slower nanowire elongation rates and faster for island growth relative to refill. Larger concentration oscillations suppress the electron-to-hole ratio and substantially enhance the tendency for the p-type Si doping of GaAs nanowires, which is a typical picture in molecular beam epitaxy. The oscillations become weaker and may finally disappear in vapor deposition techniques such as hydride vapor phase epitaxy, where the n-type Si doping of GaAs nanowires is more easily achievable.
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spelling pubmed-77123322020-12-04 Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires Dubrovskii, Vladimir G. Hijazi, Hadi Nanomaterials (Basel) Article III–V nanowires grown by the vapor–liquid–solid method often show self-regulated oscillations of group V concentration in a catalyst droplet over the monolayer growth cycle. We investigate theoretically how this effect influences the electron-to-hole ratio in Si-doped GaAs nanowires. Several factors influencing the As depletion in the vapor–liquid–solid nanowire growth are considered, including the time-scale separation between the steps of island growth and refill, the “stopping effect” at very low As concentrations, and the maximum As concentration at nucleation and desorption. It is shown that the As depletion effect is stronger for slower nanowire elongation rates and faster for island growth relative to refill. Larger concentration oscillations suppress the electron-to-hole ratio and substantially enhance the tendency for the p-type Si doping of GaAs nanowires, which is a typical picture in molecular beam epitaxy. The oscillations become weaker and may finally disappear in vapor deposition techniques such as hydride vapor phase epitaxy, where the n-type Si doping of GaAs nanowires is more easily achievable. MDPI 2020-04-27 /pmc/articles/PMC7712332/ /pubmed/32349326 http://dx.doi.org/10.3390/nano10050833 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Dubrovskii, Vladimir G.
Hijazi, Hadi
Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires
title Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires
title_full Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires
title_fullStr Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires
title_full_unstemmed Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires
title_short Oscillations of As Concentration and Electron-to-Hole Ratio in Si-Doped GaAs Nanowires
title_sort oscillations of as concentration and electron-to-hole ratio in si-doped gaas nanowires
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7712332/
https://www.ncbi.nlm.nih.gov/pubmed/32349326
http://dx.doi.org/10.3390/nano10050833
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