Dr Fernando Salazar Posadas

@article{JIMENEZSANCHEZ2024110526,

title = {DFT insight into the structural, vibrational, and electronic properties of thin [110] Ge nanowires as anodic material for Li batteries},

author = {Ricardo Jim\'{e}nez-S\'{a}nchez and Pedro Morales-Vergara and Alma R. Heredia and Jacqueline Rebollo-Paz and \'{A}lvaro Miranda and Alejandro Trejo and Fernando Salazar and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S2352492824025078},

doi = {https://doi.org/10.1016/j.mtcomm.2024.110526},

issn = {2352-4928},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Materials Today Communications},

volume = {41},

pages = {110526},

abstract = {Germanium nanowires could be used to improve as anodic materials since their charge rate is better than that of the current graphite electrodes. In this work, we present a Density Functional Theory study of the effect of interstitial Li atoms on the vibrational, electronic, and mechanical properties of ultrathin hydrogen-passivated Ge nanowires (HGeNWs) with diamond structure, grown along the [110] crystallographic direction, and with a diameter of ∼14.4 r{A}. The interstitial Li atoms were placed at the tetrahedral positions (Td) reported as the more favorable ones. The phonon band structure of the HGeNWs reveals the existence of high frequency vibrations due to the hydrogen atoms at the nanowire surface. The effect of one interstitial Li atom in the nanowire leads to the apparition of three flat phonon bands almost independent of the collective vibrational states of the nanowire, reflecting a weak interaction between the Li atom and the neighboring ones; and a shift of the high vibrational modes to lower frequencies that results in more dispersive states. The electronic band structure confirms a transition from semiconducting to metallic behavior by adding a single Li interstitial atom per unit cell. The formation energies indicate that the nanowires with interstitial Li atoms are stable, and the average binding energy per Li atom slightly increases as a function of the concentration of Li atoms. The insertion of Li atoms in the nanowire leads to a volumetric expansion, without fracture or broken bonds. Even more, the redistribution of the electronic charge due to the Li atoms give the Ge-Ge bonds more axial elasticity and the values of the modulus of Young are almost constant for all studied concentrations of Li atoms. These theoretical results indicate an improvement of mechanical and electronic properties of Ge nanowires through the addition of interstitial Li atoms that could be important for their use as anodes in rechargeable Li batteries.},

keywords = {Anodic materials, Density Functional Theory, Ge nanowires, Li batteries},

pubstate = {published},

tppubtype = {article}

}

@article{GONZALEZ2023106840,

title = {Exploring the electronic and mechanical properties of lithium-decorated silicon carbide nanowires for energy storage},

author = {Mario Gonzalez and Fernando Salazar and Alejandro Trejo and \'{A}lvaro Miranda and Roc\'{i}o Nava and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S2352152X23002372},

doi = {https://doi.org/10.1016/j.est.2023.106840},

issn = {2352-152X},

year  = {2023},

date = {2023-01-01},

journal = {Journal of Energy Storage},

volume = {62},

pages = {106840},

abstract = {The high chemical stability of silicon carbide (SiC) is attractive to inhibit unwanted side chemical reaction and prolongate the cyclability performance of lithium ion batteries anodes. However, SiC has high surface lithiation energy barrier due to its intrinsic nature and the low electrical conductivity limited the application in this area. The surface modification of SiC is an alternative to boost the lithiation\textendashdelithiation kinetics. Hydrogen incorporation on SiC surface is extensively used in semiconductor industry to passivate electrically active centers. In this work, we present a theoretical study of the effect of surface lithium (Li) atoms on the electronic and mechanical properties of hydrogen passivated SiC nanowires (H-SiCNWs) with zinc-blende structure. The results show that the adsorption of Li on the carbon (C) atoms at the surface of the nanowire introduces new electronic states within the former band gap of the H-SiCNWs, whose main contribution comes from the C and silicon (Si) atoms in the valence and conduction bands, respectively. Moreover, the number of new bands within the former band gap increases as a function of the concentration of Li atoms and the systems remain as intrinsic semiconductors up to the maximum Li concentrations. The formation energy reveals that the stability of the nanowires increases when the concentration of Li atoms augments. Moreover, the values of the open circuit voltage are found between 1.6 and 1.9 V for all studied concentrations of Li atoms and morphologies. The charge population analysis indicates that the Li atoms give up charge to the C ones resulting in ionic bonds. On the other hand, the Young modulus of the H-SiCNWs increases when their diameter augments and their values are lower than that of the bulk SiC. Besides, the Young modulus slightly diminishes when the concentration of Li grows, then the mechanical resistance could offer a large useful life of the electrode. Finally, the maximum theoretical storage capacity values indicate that the SiC nanowires (SiCNWs) are good potential anodic materials for rechargeable Li-ion batteries.},

keywords = {Anodes, Density Functional Theory, Lithium ion batteries, SiC nanowires},

pubstate = {published},

tppubtype = {article}

}

@article{SOSA202120245,

title = {Alkali and transition metal atom-functionalized germanene for hydrogen storage: A DFT investigation},

author = {Akari Narayama Sosa and Francisco Santiago and \'{A}lvaro Miranda and Alejandro Trejo and Fernando Salazar and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0360319920315329},

doi = {https://doi.org/10.1016/j.ijhydene.2020.04.129},

issn = {0360-3199},

year  = {2021},

date = {2021-01-01},

journal = {International Journal of Hydrogen Energy},

volume = {46},

number = {38},

pages = {20245-20256},

abstract = {In this work, we have performed density functional theory-based calculations to study the adsorption of H2 molecules on germanene decorated with alkali atoms (AM) and transition metal atoms (TM). The cohesive energy indicates that interaction between AM (TM) atoms and germanene is strong. The values of the adsorption energies of H2 molecules on the AM or TM atoms are in the range physisorption. The K-decorated germanene has the largest storage capacity, being able to bind up to six H2 molecules, whereas the Au and Na atoms adsorbed five and four H2 molecules, respectively. Li and Ag atoms can bind a maximum of three H2 molecules, while Cu-decorated germanene only adsorbed one H2 molecule. Formation energies show that all the studied cases of H2 molecules adsorbed on AM and TM atom-decorated germanene are energetically favorable. These results indicate that decorated germanene can serve as a hydrogen storage system.},

note = {International Journal of Hydrogen Energy Special Issue devoted to the 32nd International Conference ECOS 2019},

keywords = {2D materials, Decoration, Density Functional Theory, Germanene, Hydrogen storage, Renewable energy storage},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/jcc.26421,

title = {Effects of lithium on the electronic properties of porous Ge as anode material for batteries},

author = {Akari Narayama Sosa and Israel Gonz\'{a}lez and Alejandro Trejo and \'{A}lvaro Miranda and Fernando Salazar and Miguel Cruz-Irisson},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jcc.26421},

doi = {https://doi.org/10.1002/jcc.26421},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Computational Chemistry},

volume = {41},

number = {31},

pages = {2653-2662},

abstract = {Abstract Recently, the need of improvement of energy storage has led to the development of Lithium batteries with porous materials as electrodes. Porous Germanium (pGe) has shown promise for the development of new generation Li-ion batteries due to its excellent electronic, and chemical properties, however, the effect of lithium in its properties has not been studied extensively. In this contribution, the effect of surface and interstitial Li on the electronic properties of pGe was studied using a first-principles density functional theory scheme. The porous structures were modeled by removing columns of atoms in the [001] direction and the surface dangling bonds were passivated with H atoms, and then replaced with Li atoms. Also, the effect of a single interstitial Li in the Ge was analyzed. The transition state and the diffusion barrier of the Li in the Ge structure were studied using a quadratic synchronous transit scheme.},

keywords = {Density Functional Theory, electronic properties, Li-ion batteries, porous germanium, transition state},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/qua.25713,

title = {Quantum confinement effects on the harmful-gas-sensing properties of silicon nanowires},

author = {Francisco Santiago and \'{A}lvaro Miranda and Alejandro Trejo and Fernando Salazar and Eliel Carvajal and Miguel Cruz-Irisson and Luis A. P\'{e}rez},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qua.25713},

doi = {https://doi.org/10.1002/qua.25713},

year  = {2018},

date = {2018-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {118},

number = {20},

pages = {e25713},

abstract = {Abstract In this work, the effects of the adsorption of different toxic gas molecules CO, NO, NO2, and SO2 on the electronic structure of hydrogen-passivated, [111]-oriented, silicon nanowires (H-SiNWs), are studied through density functional theory. To analyze the effects of quantum confinement, three nanowire diameters are considered. The results show that the adsorption energies are almost independent of the nanowire diameter with NO2 being the most strongly adsorbed molecule (∼3.44 eV). The electronic structure of small-diameter H-SiNWs is modified due to the creation of isolated defect-like states on molecule adsorption. However, these discrete levels are eventually hybridized with the former nanowire states as the nanowire diameter increases and quantum confinement effects become less evident. Hence, there is a range of small nanowire diameters with distinctive band gaps and adsorption energies for each molecule species.},

keywords = {Density Functional Theory, Nanowires, Sensors, silicon, toxic gases},

pubstate = {published},

tppubtype = {article}

}