Dr Alejandro Trejo Baños

@article{CUEVAS20128360,

title = {Ab-initio modeling of oxygen on the surface passivation of 3CSiC nanostructures},

author = {J. L. Cuevas and A. Trejo and M. Calvino and E. Carvajal and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0169433212006289},

doi = {https://doi.org/10.1016/j.apsusc.2012.03.175},

issn = {0169-4332},

year  = {2012},

date = {2012-01-01},

journal = {Applied Surface Science},

volume = {258},

number = {21},

pages = {8360-8365},

abstract = {In this work the effect of OH on the electronic states of H-passivated 3CSiC nanostructures, was studied by means of Density Functional Theory. We compare the electronic band structure for a [111]-oriented nanowire with total H, OH passivation and a combination of both. Also the electronic states of a porous silicon carbide case (PSiC) a C-rich pore surface in which the dangling bonds on the surface are saturated with H and OH was studied. The calculations show that the surface replacement of H with OH radicals is always energetically favorable and more stable. In all cases the OH passivation produced a similar effect than the H passivation, with electronic band gap of lower energy value than the H-terminated phase. When the OH groups are attached to C atoms, the band gap feature is changed from direct to indirect. The results indicate the possibility of band gap engineering on SiC nanostructures through the surface passivation species.},

note = {VII International Workshop on Semiconductor Surface Passivation, KRAK\'{O}W, POLAND, September 11 - 15, 2011},

keywords = {Density Functional Theory, Nanowires, Porous semiconductors, Silicon carbide},

pubstate = {published},

tppubtype = {article}

}

@article{MIRANDA20121230,

title = {Interconnection effects on the electronic and optical properties of Ge nanostructures: A semi-empirical approach},

author = {A. Miranda and A. Trejo and E. Canadell and R. Rurali and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S1386947712000318},

doi = {https://doi.org/10.1016/j.physe.2012.01.017},

issn = {1386-9477},

year  = {2012},

date = {2012-01-01},

journal = {Physica E: Low-dimensional Systems and Nanostructures},

volume = {44},

number = {7},

pages = {1230-1235},

abstract = {A supercell model is applied to a semi-empirical sp3s⁎ tight-binding (TB) approach to calculate the electronic band gap and imaginary part of the dielectric function of two Ge nanostructures\textemdashordered arrays of pores and stand-alone nanowires\textemdashand one example of their interconnections. The pores are modeled by removing columns of Ge atoms in the [001] direction. The results of the variation band gap are compared with those obtained by TB-sp3, TB-sp3d5s⁎, density functional theory (DFT), and experimental data. The imaginary part of the dielectric function is calculated by including both intra-atomic and inter-atomic dipole matrices using (for both) the interconnected and free standing (chessboard-like) models for the Ge skeleton. The calculation shows that although the intra-atomic matrix elements are small in magnitude a quantitative treatment of the optical absorption spectrum of Ge nanostructures may not be possible without the inclusion of these matrix elements. Finally, the calculations confirm that also ordered porous germanium (PGe) show a clear quantum confinement signature, even though the wave functions could in principle behave like delocalized Bloch states.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{57030389006,

title = {Theoretical study of the electronic band gap in B-SiC nanowires},

author = {M. Ramos A. Calvino Trejo},

url = {https://www.redalyc.org/articulo.oa?id=57030389006},

issn = {0035-001X},

year  = {2011},

date = {2011-01-01},

journal = {Revista Mexicana de F\'{i}sica},

keywords = {Keywords; Density functional theory; nanowires; silicon carbide.; Descriptores; Teor\'{i}a del funcional de la densidad; nanoalambres; carburo de silicio.},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/qua.22647,

title = {Chemical surface passivation of 3C-SiC nanocrystals: A first-principle study},

author = {A. Trejo and M. Calvino and M. Cruz-Irisson},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qua.22647},

doi = {https://doi.org/10.1002/qua.22647},

year  = {2010},

date = {2010-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {110},

number = {13},

pages = {2455-2461},

abstract = {Abstract The effect of the chemical surface passivation, with hydrogen atoms, on the energy band gap of porous cubic silicon carbide (PSiC) was investigated. The pores are modeled by means of the supercell technique, in which columns of Si and/or C atoms are removed along the [001] direction. Within this supercell model, morphology effects can be analyzed in detail. The electronic band structure is performed using the density functional theory based on the generalized gradient approximation. Two types of pores are studied: C-rich and Si-rich pores surface. The enlargement of energy band gap is greater in the C-rich than Si-rich pores surface. This supercell model emphasizes the interconnection between 3C-SiC nanocrystals, delocalizing the electronic states. However, the results show a clear quantum confinement signature, which is contrasted with that of nanowire systems. The calculation shows a significant response to changes in surface passivation with hydrogen. The chemical tuning of the band gap opens the possibility plenty applications in nanotechnology. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2455\textendash2461, 2010},

keywords = {Density Functional Theory, Porous silicon carbide, silicon carbide nanowires},

pubstate = {published},

tppubtype = {article}

}