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High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes
Hexagonal boron nitride (hBN) has attracted a great deal of attention as a key component in van der Waals (vdW) heterostructures, and as a wide band gap material for deep-ultraviolet devices. We have recently demonstrated plasma-assisted molecular beam epitaxy (PA-MBE) of hBN layers on substrates of...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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MDPI
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073546/ https://www.ncbi.nlm.nih.gov/pubmed/29966333 http://dx.doi.org/10.3390/ma11071119 |
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author | Cheng, Tin S. Summerfield, Alex Mellor, Christopher J. Khlobystov, Andrei N. Eaves, Laurence Foxon, C. Thomas Beton, Peter H. Novikov, Sergei V. |
author_facet | Cheng, Tin S. Summerfield, Alex Mellor, Christopher J. Khlobystov, Andrei N. Eaves, Laurence Foxon, C. Thomas Beton, Peter H. Novikov, Sergei V. |
author_sort | Cheng, Tin S. |
collection | PubMed |
description | Hexagonal boron nitride (hBN) has attracted a great deal of attention as a key component in van der Waals (vdW) heterostructures, and as a wide band gap material for deep-ultraviolet devices. We have recently demonstrated plasma-assisted molecular beam epitaxy (PA-MBE) of hBN layers on substrates of highly oriented pyrolytic graphite at high substrate temperatures of ~1400 °C. The current paper will present data on the high-temperature PA-MBE growth of hBN layers using a high-efficiency radio-frequency (RF) nitrogen plasma source. Despite more than a three-fold increase in nitrogen flux with this new source, we saw no significant increase in the growth rates of the hBN layers, indicating that the growth rate of hBN layers is controlled by the boron arrival rate. The hBN thickness increases to 90 nm with decrease in the growth temperature to 1080 °C. However, the decrease in the MBE temperature led to a deterioration in the optical properties of the hBN. The optical absorption data indicates that an increase in the active nitrogen flux during the PA-MBE process improves the optical properties of hBN and suppresses defect related optical absorption in the energy range 5.0–5.5 eV. |
format | Online Article Text |
id | pubmed-6073546 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-60735462018-08-13 High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes Cheng, Tin S. Summerfield, Alex Mellor, Christopher J. Khlobystov, Andrei N. Eaves, Laurence Foxon, C. Thomas Beton, Peter H. Novikov, Sergei V. Materials (Basel) Article Hexagonal boron nitride (hBN) has attracted a great deal of attention as a key component in van der Waals (vdW) heterostructures, and as a wide band gap material for deep-ultraviolet devices. We have recently demonstrated plasma-assisted molecular beam epitaxy (PA-MBE) of hBN layers on substrates of highly oriented pyrolytic graphite at high substrate temperatures of ~1400 °C. The current paper will present data on the high-temperature PA-MBE growth of hBN layers using a high-efficiency radio-frequency (RF) nitrogen plasma source. Despite more than a three-fold increase in nitrogen flux with this new source, we saw no significant increase in the growth rates of the hBN layers, indicating that the growth rate of hBN layers is controlled by the boron arrival rate. The hBN thickness increases to 90 nm with decrease in the growth temperature to 1080 °C. However, the decrease in the MBE temperature led to a deterioration in the optical properties of the hBN. The optical absorption data indicates that an increase in the active nitrogen flux during the PA-MBE process improves the optical properties of hBN and suppresses defect related optical absorption in the energy range 5.0–5.5 eV. MDPI 2018-06-30 /pmc/articles/PMC6073546/ /pubmed/29966333 http://dx.doi.org/10.3390/ma11071119 Text en © 2018 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 Cheng, Tin S. Summerfield, Alex Mellor, Christopher J. Khlobystov, Andrei N. Eaves, Laurence Foxon, C. Thomas Beton, Peter H. Novikov, Sergei V. High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes |
title | High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes |
title_full | High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes |
title_fullStr | High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes |
title_full_unstemmed | High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes |
title_short | High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes |
title_sort | high-temperature molecular beam epitaxy of hexagonal boron nitride with high active nitrogen fluxes |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073546/ https://www.ncbi.nlm.nih.gov/pubmed/29966333 http://dx.doi.org/10.3390/ma11071119 |
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