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Gallium clustering and structural effects of hydrogenation in InGaN/GaN nanostructures
- Source :
- Journal of applied physics 124 (2018). doi:10.1063/1.5051529, info:cnr-pdr/source/autori:Ciatto, Gianluca; Pettinari, Giorgio; Polimeni, Antonio/titolo:Gallium clustering and structural effects of hydrogenation in InGaN%2FGaN nanostructures/doi:10.1063%2F1.5051529/rivista:Journal of applied physics/anno:2018/pagina_da:/pagina_a:/intervallo_pagine:/volume:124
- Publication Year :
- 2018
- Publisher :
- American Institute of Physics, New York, N.Y. , Stati Uniti d'America, 2018.
-
Abstract
- We addressed the issue of atomic ordering in a series of In-rich In xGa 1 − xN epilayers grown on a GaN/AlN/sapphire(0001) epitaxial template by quantitatively measuring the Ga-cation coordination in the second atomic shell of Ga. We used Diffraction Anomalous Fine Structure Spectroscopy (DAFS) at the Ga K-edge to select the signal coming from the Ga atoms in the epilayer and eliminate any contribution from the buffer layer. DAFS measurements were also performed on hydrogenated epilayers in order to investigate the possible formation of Ga-H complexes. We find that deviation from cation random distribution in the form of Ga clustering is present in both untreated and hydrogenated samples and that in the latter ones the second atomic shell around Ga is modified, suggesting an additional perturbation of the cation sublattice related to hydrogen. However, comparing the present results with In K-edge x-ray absorption spectra previously reported, we conclude that the formation of Ga-H complexes vs. In-H ones is unlikely. Cation clustering has to be anyway taken into account as a possible channel playing in the determination of the optical bandgap of these technology-oriented semiconductors.We addressed the issue of atomic ordering in a series of In-rich In xGa 1 − xN epilayers grown on a GaN/AlN/sapphire(0001) epitaxial template by quantitatively measuring the Ga-cation coordination in the second atomic shell of Ga. We used Diffraction Anomalous Fine Structure Spectroscopy (DAFS) at the Ga K-edge to select the signal coming from the Ga atoms in the epilayer and eliminate any contribution from the buffer layer. DAFS measurements were also performed on hydrogenated epilayers in order to investigate the possible formation of Ga-H complexes. We find that deviation from cation random distribution in the form of Ga clustering is present in both untreated and hydrogenated samples and that in the latter ones the second atomic shell around Ga is modified, suggesting an additional perturbation of the cation sublattice related to hydrogen. However, comparing the present results with In K-edge x-ray absorption spectra previously reported, we conclude that the formation of Ga-H complexes vs. In-H...
- Subjects :
- Diffraction
Materials science
Absorption spectroscopy
Hydrogen
Band gap
General Physics and Astronomy
chemistry.chemical_element
02 engineering and technology
021001 nanoscience & nanotechnology
Epitaxy
dilute nitrides
01 natural sciences
Molecular physics
chemistry
hydrogen
0103 physical sciences
Sapphire
semicondutors
Gallium
010306 general physics
0210 nano-technology
Spectroscopy
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Journal of applied physics 124 (2018). doi:10.1063/1.5051529, info:cnr-pdr/source/autori:Ciatto, Gianluca; Pettinari, Giorgio; Polimeni, Antonio/titolo:Gallium clustering and structural effects of hydrogenation in InGaN%2FGaN nanostructures/doi:10.1063%2F1.5051529/rivista:Journal of applied physics/anno:2018/pagina_da:/pagina_a:/intervallo_pagine:/volume:124
- Accession number :
- edsair.doi.dedup.....8a56de9681bda50482a8a73fed453e7c
- Full Text :
- https://doi.org/10.1063/1.5051529