Dr Álvaro Miranda Durán

@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}

}

@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}

}

@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}

}