2023
Jiménez-Sánchez, Ricardo; Pérez-Figueroa, Sara E.; Trejo-Baños, Alejandro; Miranda, Álvaro; Salazar, Fernando; Cruz-Irisson, Miguel
Surface Li effects on the electronic properties of GaAs nanowires: A first principles approach Artículo de revista
En: Surfaces and Interfaces, vol. 38, pp. 102745, 2023, ISSN: 2468-0230.
Resumen | Enlaces | BibTeX | Etiquetas: DFT, GaAs nanowires, Surface passivation
@article{JIMENEZSANCHEZ2023102745,
title = {Surface Li effects on the electronic properties of GaAs nanowires: A first principles approach},
author = {Ricardo Jim\'{e}nez-S\'{a}nchez and Sara E. P\'{e}rez-Figueroa and Alejandro Trejo-Ba\~{n}os and \'{A}lvaro Miranda and Fernando Salazar and Miguel Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S2468023023001153},
doi = {https://doi.org/10.1016/j.surfin.2023.102745},
issn = {2468-0230},
year = {2023},
date = {2023-01-01},
journal = {Surfaces and Interfaces},
volume = {38},
pages = {102745},
abstract = {The quest for the improvement of Li-Ion batteries has directed attention towards semiconductor nanostructures, like nanowires. However, the surface interactions and effects of Li on the electronic properties of these nanostcrutures has been less explored. Especially the possible modifications to the properties of GaAs nanowires that arise from having Li on its surface have been seldom studied. In this work, we employed Density Functional Theory to study the effects of surface Li on the electronic properties of H passivated GaAs nanowires grown along the [111] direction. To determinate the isolated effects of Li on either surface Ga or As, only Li bonded to either Ga[GaAsNW_Ga-Li] or As[GaAsNW_As-Li] were considered, and up to 6 Li were placed on the respective nanowire surfaces. The results indicate that the energy gap is a function of the Li concentration, the nanowire diameter and the placement of Li on the nanowire surface. The binding energy is independent of the number of Li on the nanowire surface, where the GaAsNW_Ga-Li has slower binding energies compared to the GaAsNW_As-Li, but the binding energies and band gaps in both cases are high, which would hinder the application of these nanowires in Li ion batteries.},
keywords = {DFT, GaAs nanowires, Surface passivation},
pubstate = {published},
tppubtype = {article}
}
The quest for the improvement of Li-Ion batteries has directed attention towards semiconductor nanostructures, like nanowires. However, the surface interactions and effects of Li on the electronic properties of these nanostcrutures has been less explored. Especially the possible modifications to the properties of GaAs nanowires that arise from having Li on its surface have been seldom studied. In this work, we employed Density Functional Theory to study the effects of surface Li on the electronic properties of H passivated GaAs nanowires grown along the [111] direction. To determinate the isolated effects of Li on either surface Ga or As, only Li bonded to either Ga[GaAsNW_Ga-Li] or As[GaAsNW_As-Li] were considered, and up to 6 Li were placed on the respective nanowire surfaces. The results indicate that the energy gap is a function of the Li concentration, the nanowire diameter and the placement of Li on the nanowire surface. The binding energy is independent of the number of Li on the nanowire surface, where the GaAsNW_Ga-Li has slower binding energies compared to the GaAsNW_As-Li, but the binding energies and band gaps in both cases are high, which would hinder the application of these nanowires in Li ion batteries.
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.
2012
Calvino, M.; Trejo, A.; Cuevas, J. L.; Carvajal, E.; Duchén, G. I.; Cruz-Irisson, M.
A Density Functional Theory study of the chemical surface modification of β-SiC nanopores Artículo de revista
En: Materials Science and Engineering: B, vol. 177, no 16, pp. 1482-1486, 2012, ISSN: 0921-5107, (Advances in Semiconducting Materials).
Resumen | Enlaces | BibTeX | Etiquetas: Density Functional Theory, Porous silicon carbide, Surface passivation
@article{CALVINO20121482,
title = {A Density Functional Theory study of the chemical surface modification of β-SiC nanopores},
author = {M. Calvino and A. Trejo and J. L. Cuevas and E. Carvajal and G. I. Duch\'{e}n and M. Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S0921510712000918},
doi = {https://doi.org/10.1016/j.mseb.2012.02.009},
issn = {0921-5107},
year = {2012},
date = {2012-01-01},
journal = {Materials Science and Engineering: B},
volume = {177},
number = {16},
pages = {1482-1486},
abstract = {The dependence of the electronic band structure and density of states on the chemical surface passivation of cubic porous silicon carbide (PSiC) is investigated by means of the ab-initio Density Functional Theory and the supercell method in which pores with different sizes and morphologies were created. The porous structures were modeled by removing atoms in the [001] direction producing two different surface chemistries; one with both Silicon (Si) and Carbon (C) atoms and the other with only Si or C atoms. The changes in the electronic band gap due to a Si-rich and C-rich phase in the porous surfaces are studied with two kind of surface passivation, one with hydrogen atoms and other with a combination between hydrogen and oxygen atoms. The calculations show that for the hydrogenated case, the band gap is larger for the C-rich than for the Si-rich case. For the partial oxygenation the tendency is contrary, by decreasing and increasing the band gap for the C-rich and Si-rich configuration, respectively, according to the percentage of oxygen in the pore surface.},
note = {Advances in Semiconducting Materials},
keywords = {Density Functional Theory, Porous silicon carbide, Surface passivation},
pubstate = {published},
tppubtype = {article}
}
The dependence of the electronic band structure and density of states on the chemical surface passivation of cubic porous silicon carbide (PSiC) is investigated by means of the ab-initio Density Functional Theory and the supercell method in which pores with different sizes and morphologies were created. The porous structures were modeled by removing atoms in the [001] direction producing two different surface chemistries; one with both Silicon (Si) and Carbon (C) atoms and the other with only Si or C atoms. The changes in the electronic band gap due to a Si-rich and C-rich phase in the porous surfaces are studied with two kind of surface passivation, one with hydrogen atoms and other with a combination between hydrogen and oxygen atoms. The calculations show that for the hydrogenated case, the band gap is larger for the C-rich than for the Si-rich case. For the partial oxygenation the tendency is contrary, by decreasing and increasing the band gap for the C-rich and Si-rich configuration, respectively, according to the percentage of oxygen in the pore surface.
