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Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations

Silicon carbide has been used in a variety of applications including solar cells due to its high stability. The high bandgap of pristine SiC, necessitates nonstoichiometric silicon carbide materials to be considered to tune the band gap for efficient solar light absorptions. In this regards, thermod...

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Autores principales: Alkhaldi, Noura D., Barman, Sajib K., Huda, Muhammad N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895658/
https://www.ncbi.nlm.nih.gov/pubmed/31844763
http://dx.doi.org/10.1016/j.heliyon.2019.e02908
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author Alkhaldi, Noura D.
Barman, Sajib K.
Huda, Muhammad N.
author_facet Alkhaldi, Noura D.
Barman, Sajib K.
Huda, Muhammad N.
author_sort Alkhaldi, Noura D.
collection PubMed
description Silicon carbide has been used in a variety of applications including solar cells due to its high stability. The high bandgap of pristine SiC, necessitates nonstoichiometric silicon carbide materials to be considered to tune the band gap for efficient solar light absorptions. In this regards, thermodynamically stable Si-rich Si(x)C(1-x) materials can be used in solar cell applications without requiring the expensive pure grade silicon or pure grade silicon carbide. In this work, we have used density functional theory (DFT) to examine the stability of various polymorphs of silicon carbide such as 2H–SiC, 4H–SiC, 6H–SiC, 8H–SiC, 10H–SiC, wurtzite, naquite, and diamond structures to produce stable structures of Si-rich Si(x)C(1-x). We have systematically replaced the carbon atoms by silicon to lower the band gap and found that the configurations of these excess silicon atoms play a significant role in the stability of Si-rich Si(x)C(1-x). Hence, we have investigated different configurations of silicon and carbon atoms in these silicon carbide structures to obtain suitable Si(x)C(1-x) materials with tailored band gaps. The results indicate that 6H-Si(x)C(1-x) is thermodynamically the most favorable structure within the scope of this study. In addition, Si substitution for C sites in 6H–SiC enhances the solar absorption, as well as shifts the absorption spectra toward the lower photon energy region. In addition, in the visible range the absorption coefficients are much higher than the pristine SiC.
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spelling pubmed-68956582019-12-16 Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations Alkhaldi, Noura D. Barman, Sajib K. Huda, Muhammad N. Heliyon Article Silicon carbide has been used in a variety of applications including solar cells due to its high stability. The high bandgap of pristine SiC, necessitates nonstoichiometric silicon carbide materials to be considered to tune the band gap for efficient solar light absorptions. In this regards, thermodynamically stable Si-rich Si(x)C(1-x) materials can be used in solar cell applications without requiring the expensive pure grade silicon or pure grade silicon carbide. In this work, we have used density functional theory (DFT) to examine the stability of various polymorphs of silicon carbide such as 2H–SiC, 4H–SiC, 6H–SiC, 8H–SiC, 10H–SiC, wurtzite, naquite, and diamond structures to produce stable structures of Si-rich Si(x)C(1-x). We have systematically replaced the carbon atoms by silicon to lower the band gap and found that the configurations of these excess silicon atoms play a significant role in the stability of Si-rich Si(x)C(1-x). Hence, we have investigated different configurations of silicon and carbon atoms in these silicon carbide structures to obtain suitable Si(x)C(1-x) materials with tailored band gaps. The results indicate that 6H-Si(x)C(1-x) is thermodynamically the most favorable structure within the scope of this study. In addition, Si substitution for C sites in 6H–SiC enhances the solar absorption, as well as shifts the absorption spectra toward the lower photon energy region. In addition, in the visible range the absorption coefficients are much higher than the pristine SiC. Elsevier 2019-11-27 /pmc/articles/PMC6895658/ /pubmed/31844763 http://dx.doi.org/10.1016/j.heliyon.2019.e02908 Text en © 2019 Published by Elsevier Ltd. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Article
Alkhaldi, Noura D.
Barman, Sajib K.
Huda, Muhammad N.
Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
title Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
title_full Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
title_fullStr Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
title_full_unstemmed Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
title_short Crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
title_sort crystal structures and the electronic properties of silicon-rich silicon carbide materials by first principle calculations
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895658/
https://www.ncbi.nlm.nih.gov/pubmed/31844763
http://dx.doi.org/10.1016/j.heliyon.2019.e02908
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