El Dr. Alejandro Trejo se graduó de doctorado en Comunicaciones y Electrónica en el 2015 en la Escuela Superior de Ingeniería Mecánica y Eléctrica unidad Culhuacan, desde el 2016 hasta la fecha realiza investigación sobre las propiedades electrónicas, ópticas y vibracionales de semiconductores binarios nanoestructurados, y sus posibles aplicaciones en fuentes alternas de energía en celdas solares, almacenamiento de energía, y emisión de fotones únicos para computación y comunicaciones cuánticas. Ha publicado más de 30 artículos en revistas internacionales indizadas en el JCR y ha participado en más de 50 congresos nacionales e internacionales, con trabajos en modalidad, poster, oral y conferencia magistral. Ha graduado a 9 estudiantes de maestría y asesorado dos proyectos terminales de licenciatura. Se encuentra asesorando o co-asesorando actualmente dos tesis del doctorado en Energía y una en el Doctorado en Comunicaciones y Electrónica. Entre sus reconocimientos se encuentran: Investigador nacional nivel 1 del sistema nacional de investigadores desde el 2015 hasta la fecha, ganador premio a la investigación del instituto politécnico nacional en la modalidad de Investigación realizada por jóvenes investigadores, dos veces ganador de la Presea Lázaro Cárdenas por mejor aprovechamiento en maestría y doctorado, Premio a la mejor Tesis de Maestría del Instituto Politécnico Nacional, Premio a la Mejor tesis de doctorado del Instituto de Investigaciones en Materiales de La Universidad Nacional Autónoma de México, mención honorífica en su examen de grado de Maestría y Doctorado, y en el examen profesional de Licenciatura. Miembro de las redes de Energía y Micro y Nano tecnología del Instituto Politécnico Nacional.
Enlaces a perfiles en distintas plataformas:
Cuevas, J. L.; Ojeda, M.; Calvino, M.; Trejo, A.; Salazar, F.; Miranda, A.; Perez, L. A.; Cruz-Irisson, M.
Theoretical approach to the phonon modes of GaSb nanowires Artículo de revista
En: Physica E: Low-dimensional Systems and Nanostructures, vol. 143, pp. 115372, 2022, ISSN: 1386-9477.
Resumen | Enlaces | BibTeX | Etiquetas: DFT, Gallium Antimonide, Nanowires, Phonons
@article{CUEVAS2022115372,
title = {Theoretical approach to the phonon modes of GaSb nanowires},
author = {J. L. Cuevas and M. Ojeda and M. Calvino and A. Trejo and F. Salazar and A. Miranda and L. A. Perez and M. Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S1386947722002077},
doi = {https://doi.org/10.1016/j.physe.2022.115372},
issn = {1386-9477},
year = {2022},
date = {2022-01-01},
journal = {Physica E: Low-dimensional Systems and Nanostructures},
volume = {143},
pages = {115372},
abstract = {Gallium Antimonide nanowires (GaSbNWs) have attracted much attention due to their possible applications in mid infrared detectors, however, there are only few theoretical investigations about this material and almost none regarding its vibrational properties. In this work the phonon modes of GaSbNWs were studied using the density functional theory with the finite displacement supercell scheme. The nanowires are modeled by removing atoms outside from a circumference along the [1 1 1] direction. All surface dangling bonds were passivated with hydrogen atoms. The results show that the expected red-shift of the highest frequency modes of GaSb are hindered by low frequency H bond bending modes. Three clearly distinguishable frequency intervals were observed: One with vibrations whose main contribution come from the Ga and Sb nanowire atoms, the second interval with main contributions from H bending modes and finally a high frequency interval where the main contributions come from H stretching modes. Also, it was observed that the radial breathing mode (RBM) decreases when the nanowire diameter increases, while the contrary tendency is observed with their specific heat (the specific heat increases as the nanowire diameter increases), except in the low temperature region where the lower diameters have higher specific heat values. These results could be important for the characterization of these nanowires with IR and Raman techniques.},
keywords = {DFT, Gallium Antimonide, Nanowires, Phonons},
pubstate = {published},
tppubtype = {article}
}
Trejo, A.; Miranda, A.; Toscano-Medina, L. K.; Vázquez-Medina, R.; Cruz-Irisson, M.
Optical vibrational modes of Ge nanowires: A computational approach Artículo de revista
En: Microelectronic Engineering, vol. 159, pp. 215-220, 2016, ISSN: 0167-9317, (Micro/Nano Devices and Systems 2015).
Resumen | Enlaces | BibTeX | Etiquetas: Density functional perturbation theory, Germanium nanowires, Phonons, Raman spectrum
@article{TREJO2016215,
title = {Optical vibrational modes of Ge nanowires: A computational approach},
author = {A. Trejo and A. Miranda and L. K. Toscano-Medina and R. V\'{a}zquez-Medina and M. Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S0167931716302258},
doi = {https://doi.org/10.1016/j.mee.2016.04.024},
issn = {0167-9317},
year = {2016},
date = {2016-01-01},
journal = {Microelectronic Engineering},
volume = {159},
pages = {215-220},
abstract = {Although Ge nanowires (GeNWs) have been extensively studied in the last decade the information about their vibrational modes is still scarce, their correct comprehension could hasten the development of new microelectronic technologies, therefore, in this work we aimed to study the vibrational properties, Raman and IR and spectrum of GeNWs using the first principles density functional perturbation theory. The nanowires are modelled in the [001] direction and all dangling bonds are passivated with H and Cl atoms. Results show that the vibrational modes can be classified in three frequency intervals, a low frequency one (between 0 and 300cm−1) of mainly GeGe vibrations, and two of GeH bending and stretching vibrations (400\textendash500cm−1 and 2000cm−1, respectively). There is a shift of the highest optical modes of GeGe vibrations compared to their bulk counterparts due to phonon confinement effects, however it is masked by some GeH bond bending modes as demonstrated by the IR and Raman responses. The Cl passivated case shows a larger number of modes at lower frequencies due to the higher mass of Cl compared to H, which in turn reduces the red shift of the highest optical modes frequencies. These results could be important for the characterization of GeNWs with different surface passivations.},
note = {Micro/Nano Devices and Systems 2015},
keywords = {Density functional perturbation theory, Germanium nanowires, Phonons, Raman spectrum},
pubstate = {published},
tppubtype = {article}
}
Trejo, A.; López-Palacios, L.; Vázquez-Medina, R.; Cruz-Irisson, M.
Theoretical approach to the phonon modes and specific heat of germanium nanowires Artículo de revista
En: Physica B: Condensed Matter, vol. 453, pp. 14-18, 2014, ISSN: 0921-4526, (Low-Dimensional Semiconductor Structures - A part of the XXII International Material Research Congress (IMRC 2013)).
Resumen | Enlaces | BibTeX | Etiquetas: Germanium, Nanowires, Phonons, Specific Heat
@article{TREJO201414,
title = {Theoretical approach to the phonon modes and specific heat of germanium nanowires},
author = {A. Trejo and L. L\'{o}pez-Palacios and R. V\'{a}zquez-Medina and M. Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S0921452614003706},
doi = {https://doi.org/10.1016/j.physb.2014.05.005},
issn = {0921-4526},
year = {2014},
date = {2014-01-01},
journal = {Physica B: Condensed Matter},
volume = {453},
pages = {14-18},
abstract = {The phonon modes and specific heat of Ge nanowires were computed using a first principles density functional theory scheme with a generalized gradient approximation and finite-displacement supercell algorithms. The nanowires were modeled in three different directions: [001], [111], and [110], using the supercell technique. All surface dangling bonds were saturated with Hydrogen atoms. The results show that the specific heat of the GeNWs at room temperature increases as the nanowire diameter decreases, regardless the orientation due to the phonon confinement and surface passivation. Also the phonon confinement effects could be observed since the highest optical phonon modes in the Ge vibration interval shifted to a lower frequency compared to their bulk counterparts.},
note = {Low-Dimensional Semiconductor Structures - A part of the XXII International Material Research Congress (IMRC 2013)},
keywords = {Germanium, Nanowires, Phonons, Specific Heat},
pubstate = {published},
tppubtype = {article}
}
Trejo, A.; Cuevas, J. L.; Vázquez-Medina, R.; Cruz-Irisson, M.
Phonon band structure of porous Ge from ab initio supercell calculation Artículo de revista
En: Microelectronic Engineering, vol. 90, pp. 141-144, 2012, ISSN: 0167-9317, (Micro&Nano 2010).
Resumen | Enlaces | BibTeX | Etiquetas: Density Functional Theory, Phonons, porous germanium, Supercell approach
@article{TREJO2012141,
title = {Phonon band structure of porous Ge from ab initio supercell calculation},
author = {A. Trejo and J. L. Cuevas and R. V\'{a}zquez-Medina and M. Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S016793171100503X},
doi = {https://doi.org/10.1016/j.mee.2011.05.007},
issn = {0167-9317},
year = {2012},
date = {2012-01-01},
journal = {Microelectronic Engineering},
volume = {90},
pages = {141-144},
abstract = {The phonon band structures for porous Ge (PGe) are performed by means of full ab initio calculations. The supercell technique is used and ordered pores are produced by removing columns of Ge atoms from their crystalline structures. The nanostructures are fully relaxed in order to obtain the minimum energy and avoid negative frequencies derived from instabilities of the system. The phonon dispersion and phonon density of states were studied using the Density Functional Theory through the finite displacement algorithm. The results show for the dehydrogenated PGe case a notable shift of the highest optical mode towards lower frequencies with respect to the bulk crystalline Ge. This fact is in agreement with the experimental data such as Raman scattering.},
note = {Micro\&Nano 2010},
keywords = {Density Functional Theory, Phonons, porous germanium, Supercell approach},
pubstate = {published},
tppubtype = {article}
}
Trejo, A.; Miranda, A.; Rivera, L. Niño; Díaz-Méndez, A.; Cruz-Irisson, M.
Phonon optical modes and electronic properties in diamond nanowires Artículo de revista
En: Microelectronic Engineering, vol. 90, pp. 92-95, 2012, ISSN: 0167-9317, (Micro&Nano 2010).
Resumen | Enlaces | BibTeX | Etiquetas: Diamond, Nanowires, Phonons, Raman scattering, Tight-binding
@article{TREJO201292,
title = {Phonon optical modes and electronic properties in diamond nanowires},
author = {A. Trejo and A. Miranda and L. Ni\~{n}o Rivera and A. D\'{i}az-M\'{e}ndez and M. Cruz-Irisson},
url = {https://www.sciencedirect.com/science/article/pii/S016793171100476X},
doi = {https://doi.org/10.1016/j.mee.2011.04.052},
issn = {0167-9317},
year = {2012},
date = {2012-01-01},
journal = {Microelectronic Engineering},
volume = {90},
pages = {92-95},
abstract = {A local bond-polarization model based on the displacement\textendashdisplacement Green’s function and the Born potential are applied to study the confined optical phonons and Raman scattering of diamond nanowires (DNWs). Also, the electronic band structure of DNWs are investigated by means of a semi-empirical tight-binding approach and compared with density functional theory within local density approximation. The supercell technique is applied to model DNWs along [001] direction preserving the crystalline diamond atomic structure. The results of both phonons and electrons show a clear quantum confinement signature. Moreover, the highest energy Raman peak shows a shift towards low frequencies respect to the bulk crystalline diamond, in agreement with experimental data.},
note = {Micro\&Nano 2010},
keywords = {Diamond, Nanowires, Phonons, Raman scattering, Tight-binding},
pubstate = {published},
tppubtype = {article}
}
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