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Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry

Gallium nitride (GaN) doped with germanium at a level of 10(20) cm(−3) is proposed as a viable material for cladding layers in blue- and green-emitting laser diodes. Spectral reflectometry and ellipsometry are used to provide evidence of a reduced index of refraction in such layers. The refractive-i...

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Autores principales: Schiavon, Dario, Mroczyński, Robert, Kafar, Anna, Kamler, Grzegorz, Levchenko, Iryna, Najda, Stephen, Perlin, Piotr
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658365/
https://www.ncbi.nlm.nih.gov/pubmed/34885522
http://dx.doi.org/10.3390/ma14237364
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author Schiavon, Dario
Mroczyński, Robert
Kafar, Anna
Kamler, Grzegorz
Levchenko, Iryna
Najda, Stephen
Perlin, Piotr
author_facet Schiavon, Dario
Mroczyński, Robert
Kafar, Anna
Kamler, Grzegorz
Levchenko, Iryna
Najda, Stephen
Perlin, Piotr
author_sort Schiavon, Dario
collection PubMed
description Gallium nitride (GaN) doped with germanium at a level of 10(20) cm(−3) is proposed as a viable material for cladding layers in blue- and green-emitting laser diodes. Spectral reflectometry and ellipsometry are used to provide evidence of a reduced index of refraction in such layers. The refractive-index contrast to undoped GaN is about 0.990, which is comparable to undoped aluminium gallium nitride (AlGaN) with an aluminium composition of 6%. Germanium-doped GaN layers are lattice-matched to native GaN substrates; therefore, they introduce no strain, cracks, and wafer bowing. Their use, in place of strained AlGaN layers, will enable significant improvements to the production process yield.
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spelling pubmed-86583652021-12-10 Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry Schiavon, Dario Mroczyński, Robert Kafar, Anna Kamler, Grzegorz Levchenko, Iryna Najda, Stephen Perlin, Piotr Materials (Basel) Article Gallium nitride (GaN) doped with germanium at a level of 10(20) cm(−3) is proposed as a viable material for cladding layers in blue- and green-emitting laser diodes. Spectral reflectometry and ellipsometry are used to provide evidence of a reduced index of refraction in such layers. The refractive-index contrast to undoped GaN is about 0.990, which is comparable to undoped aluminium gallium nitride (AlGaN) with an aluminium composition of 6%. Germanium-doped GaN layers are lattice-matched to native GaN substrates; therefore, they introduce no strain, cracks, and wafer bowing. Their use, in place of strained AlGaN layers, will enable significant improvements to the production process yield. MDPI 2021-11-30 /pmc/articles/PMC8658365/ /pubmed/34885522 http://dx.doi.org/10.3390/ma14237364 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/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 (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Schiavon, Dario
Mroczyński, Robert
Kafar, Anna
Kamler, Grzegorz
Levchenko, Iryna
Najda, Stephen
Perlin, Piotr
Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry
title Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry
title_full Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry
title_fullStr Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry
title_full_unstemmed Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry
title_short Refractive Index of Heavily Germanium-Doped Gallium Nitride Measured by Spectral Reflectometry and Ellipsometry
title_sort refractive index of heavily germanium-doped gallium nitride measured by spectral reflectometry and ellipsometry
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658365/
https://www.ncbi.nlm.nih.gov/pubmed/34885522
http://dx.doi.org/10.3390/ma14237364
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