2024
Ojeda-Martínez, Miguel; Thirumuruganandham, Saravana Prakash; Baños, Alejandro Trejo; Figueroa, José Luis Cuevas
A theoretical study of the electronic properties of hydrogenated spherical-like SiC quantum dots with C-rich and Si-rich compositions Artículo de revista
En: International Journal of Quantum Chemistry, vol. 124, no 6, pp. e27361, 2024.
Resumen | Enlaces | BibTeX | Etiquetas: C rich spherical QD, DFT, electronic properties, energy gap, Formation energy, PDOS, Si, SiC quantum dots
@article{https://doi.org/10.1002/qua.27361,
title = {A theoretical study of the electronic properties of hydrogenated spherical-like SiC quantum dots with C-rich and Si-rich compositions},
author = {Miguel Ojeda-Mart\'{i}nez and Saravana Prakash Thirumuruganandham and Alejandro Trejo Ba\~{n}os and Jos\'{e} Luis Cuevas Figueroa},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qua.27361},
doi = {https://doi.org/10.1002/qua.27361},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {International Journal of Quantum Chemistry},
volume = {124},
number = {6},
pages = {e27361},
abstract = {Abstract Quantum dots have many potential applications in opto-electronics, energy storage, catalysis, and medical diagnostics, silicon carbide quantum dots could be very attractive for many biological and technological applications due to their chemical inertness and biocompatibility, however, there are seldom theoretical studies that could boost the development of these applications. In this work, the electronic properties of hydrogenated spherical-like SiC quantum dots with C-rich and Si-rich compositions are investigated using density functional theory calculations. The quantum dots are modeled by removing atoms outside a sphere from an otherwise perfect SiC crystal, the surface dangling bonds are passivated with H atoms. Our results exhibit that the electronic properties of the SiC-QD are strongly influenced by their composition and diameter size. The energy gap is always higher than that of the crystalline SiC, making these SiC QD\'s suitable for applications at harsh temperatures. The density of states and the energy levels show that the Si-rich quantum dots had a higher density of states near the conduction band minimum, which indicates better conductivity. These results could be used to tune the electronicproperties of SiC quantum dots for optoelectronic applications.},
keywords = {C rich spherical QD, DFT, electronic properties, energy gap, Formation energy, PDOS, Si, SiC quantum dots},
pubstate = {published},
tppubtype = {article}
}
Abstract Quantum dots have many potential applications in opto-electronics, energy storage, catalysis, and medical diagnostics, silicon carbide quantum dots could be very attractive for many biological and technological applications due to their chemical inertness and biocompatibility, however, there are seldom theoretical studies that could boost the development of these applications. In this work, the electronic properties of hydrogenated spherical-like SiC quantum dots with C-rich and Si-rich compositions are investigated using density functional theory calculations. The quantum dots are modeled by removing atoms outside a sphere from an otherwise perfect SiC crystal, the surface dangling bonds are passivated with H atoms. Our results exhibit that the electronic properties of the SiC-QD are strongly influenced by their composition and diameter size. The energy gap is always higher than that of the crystalline SiC, making these SiC QD's suitable for applications at harsh temperatures. The density of states and the energy levels show that the Si-rich quantum dots had a higher density of states near the conduction band minimum, which indicates better conductivity. These results could be used to tune the electronicproperties of SiC quantum dots for optoelectronic applications.
2018
Cuevas, José Luis; Santiago, Francisco; Ramírez, Jesús; Trejo, Alejandro; Miranda, Álvaro; Pérez, Luis Antonio; Cruz-Irisson, Miguel
First principles band gap engineering of [1 1 0] oriented 3C-SiC nanowires Artículo de revista
En: Computational Materials Science, vol. 142, pp. 268-276, 2018, ISSN: 0927-0256.
Resumen | Enlaces | BibTeX | Etiquetas: DFT, Formation energy, SiC nanowires, Surface passivation
@article{CUEVAS2018268,
title = {First principles band gap engineering of [1 1 0] oriented 3C-SiC nanowires},
author = {Jos\'{e} Luis Cuevas and Francisco Santiago and Jes\'{u}s Ram\'{i}rez and Alejandro Trejo and \'{A}lvaro Miranda and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S0927025617305712},
doi = {https://doi.org/10.1016/j.commatsci.2017.10.021},
issn = {0927-0256},
year = {2018},
date = {2018-01-01},
journal = {Computational Materials Science},
volume = {142},
pages = {268-276},
abstract = {Silicon carbide nanowires offer excellent opportunities for technological applications under harsh environmental conditions, however, the 3C-SiC polytype nanowires, grown along the [1 1 0] crystallographic direction, have been rarely studied, as well as the effects of the surface passivation on their physical properties. This work addresses the effects of hydrogen passivation on the electronic band gap of silicon carbide nanowires (SiCNWs) grown along the [1 1 0] direction by means of Density Functional Theory. We compare the electronic properties of fully hydrogen-passivated SiCNWs in comparison to those of SiCNWs with a mixed passivation of oxygen and hydrogen by changing some of the surface dihydrides with SiOSi or COC bonds. The results show that regardless of the diameter and passivation, most of the nanowires have a direct band gap which suggests an increased optical activity. The surface COC bonds reduce the electronic band gap energy compared to that of the fully H-terminated phase, while the nanowires with SiOSi bonds have a larger band gap. The calculation of formation energies shows that the oxygen increases the chemical stability of the SiCNWs. These results indicate the possibility of band gap engineering on SiC nanostructures through surface passivation.},
keywords = {DFT, Formation energy, SiC nanowires, Surface passivation},
pubstate = {published},
tppubtype = {article}
}
Silicon carbide nanowires offer excellent opportunities for technological applications under harsh environmental conditions, however, the 3C-SiC polytype nanowires, grown along the [1 1 0] crystallographic direction, have been rarely studied, as well as the effects of the surface passivation on their physical properties. This work addresses the effects of hydrogen passivation on the electronic band gap of silicon carbide nanowires (SiCNWs) grown along the [1 1 0] direction by means of Density Functional Theory. We compare the electronic properties of fully hydrogen-passivated SiCNWs in comparison to those of SiCNWs with a mixed passivation of oxygen and hydrogen by changing some of the surface dihydrides with SiOSi or COC bonds. The results show that regardless of the diameter and passivation, most of the nanowires have a direct band gap which suggests an increased optical activity. The surface COC bonds reduce the electronic band gap energy compared to that of the fully H-terminated phase, while the nanowires with SiOSi bonds have a larger band gap. The calculation of formation energies shows that the oxygen increases the chemical stability of the SiCNWs. These results indicate the possibility of band gap engineering on SiC nanostructures through surface passivation.
