Publicações de José Eduardo Padilha
Dias, Victor M. S. C.; Kuritza, Danilo P.; Oliveira, Igor S. S.; Padilha, Jose E.; Miwa, Roberto H. Catenary-like rippled biphenylene/graphene lateral heterojunction Working paper 2025. Resumo | Links | BibTeX | Tags: Kuritza, Danilo; Miwa, Roberto H.; Padilha, José E. Directional dependence of the electronic and transport properties of Biphenylene under strain conditions Journal Article Em: Phys. Chem. Chem. Phys., pp. -, 2024. Resumo | Links | BibTeX | Tags: Souza, P. H.; Padilha, José E.; Miwa, Roberto H. Spin-polarized nearly-free electron channels on the Ca$_2$N electrenes Working paper 2023. Resumo | Links | BibTeX | Tags: Perin, Gabriel; Kuritza, Danilo; Barbosa, Rafael; Tresco, Gustavo; Pontes, Renato B.; Miwa, Roberto H.; Padilha, José E. Em: Phys. Rev. Mater., vol. 7, iss. 10, pp. 104003, 2023. Resumo | Links | BibTeX | Tags: Scopel, Wanderlã L.; de Lima, F. Crasto; Souza, Pedro H.; Padilha, José E.; Miwa, Roberto H. Bridging Borophene and Metal Surfaces: Structural, Electronic, and Electron Transport Properties Journal Article Em: The Journal of Physical Chemistry C, vol. 127, não 35, pp. 17556-17566, 2023. Resumo | Links | BibTeX | Tags: Barbosa, Rafael; Kuritza, Danilo; Perin, Gabriel; Miwa, Roberto H.; Pontes, R. B.; Padilha, José E. Electronic and optical properties of Janus-like hexagonal monolayer materials of group IV-VI Journal Article Em: Phys. Rev. Mater., vol. 7, iss. 1, pp. 014001, 2023.2025
@workingpaper{dias2025catenarylikerippledbiphenylenegraphenelateral,
title = {Catenary-like rippled biphenylene/graphene lateral heterojunction},
author = {Victor M. S. C. Dias and Danilo P. Kuritza and Igor S. S. Oliveira and Jose E. Padilha and Roberto H. Miwa},
url = {https://arxiv.org/abs/2503.07816},
doi = { https://doi.org/10.48550/arXiv.2503.07816},
year = {2025},
date = {2025-03-10},
urldate = {2025-01-01},
abstract = {In this study, we conduct a first-principles analysis to explore the structural and electronic properties of curved biphenylene/graphene lateral junctions (BPN/G). We start our investigation focusing on the energetic stability of BPN/G by varying the width of the graphene region, BPN/Gn. The electronic structure of BPN/Gn reveals (i) the formation of metallic channels mostly localized along the BPN stripes, where (ii) the features of the energy bands near the Fermi level are ruled by the width (n) of the graphene regions, Gn. In the sequence, we find that the hydrogenation of BPN/Gn results in a semiconductor system with a catenary-like rippled geometry. The electronic states of the hydrogenated system are mainly confined in the curved Gn regions, and the dependence of the bandgap on the width of Gn is similar to that of hydrogenated armchair graphene nanoribbons. The effects of curvature on the electronic structure, analyzed in terms of external mechanical strain, revealed that the increase/decrease of the band gap is also dictated by the width of the Gn region. Further electronic transport calculations reveal a combination of strong transmission anisotropy and the emergence of negative differential resistance. Based on these findings, we believe that rippled biphenylene/graphene systems can be useful for the design of two-dimensional nanodevices. },
keywords = {},
pubstate = {published},
tppubtype = {workingpaper}
}
2024
@article{D4CP00033A,
title = {Directional dependence of the electronic and transport properties of Biphenylene under strain conditions},
author = {Danilo Kuritza and Roberto H. Miwa and José E. Padilha},
url = {http://dx.doi.org/10.1039/D4CP00033A},
doi = {10.1039/D4CP00033A},
year = {2024},
date = {2024-03-26},
urldate = {2024-01-01},
journal = {Phys. Chem. Chem. Phys.},
pages = {-},
publisher = {The Royal Society of Chemistry},
abstract = {In this study, we investigated the electronic and electronic transport properties of biphenylene (BPN) using first-principles density functional theory (DFT) calculations combined with the non-equilibrium Green's function (NEGF) formalism. We have focused on understanding the electronic properties of BPN, and the anisotropic behavior of electronic transport upon external strain. We found the emergence of electronic stripes (ESs) on the BPN surface and the formation of type-II Dirac cone near the Fermi level. In the sequence, the electronic transport results reveal that such ESs dictate the anisotropic behavior of the transmission function. Finally, we show that the tuning of the (anisotropic) electronic current, mediated by external mechanical strain, is ruled by the energy position of the lowest unoccupied states with wave-vectors perpedicular to the ESs. This control could be advantageous for applications in nanoelectronic devices that require precise control of current direction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2023
@workingpaper{souza2023spinpolarized,
title = {Spin-polarized nearly-free electron channels on the Ca$_2$N electrenes},
author = {P. H. Souza and José E. Padilha and Roberto H. Miwa},
url = {https://arxiv.org/abs/2312.06447},
doi = {https://doi.org/10.48550/arXiv.2312.06447},
year = {2023},
date = {2023-12-12},
urldate = {2023-12-12},
abstract = {Two-dimensional (2D) materials combined with the presence of surface nearly-free electrons (NFE) have been considered quite interesting platforms to be exploited for the development of 2D electronic devices. Further incorporation of foreign elements adds a new degree of freedom to engineer the electronic as well as the magnetic properties of 2D materials. Here we have performed an ab-initio study of Ca2N, electrenes fully (i.e., both sides) adsorbed by hydrogen (H/Ca2N/H) and fluorine (F/Ca2N/F) atoms. The NFE states are suppressed in these systems, followed by the appearance of a net magnetic moment localized in the nitrogen atoms intercalated by the hydrogenated or fluorinated calcium layers. In the sequence, we have proposed lateral heterostructures combining the H/Ca2N/H or F/Ca2N/F regions with pristine Ca2N, electrenes [(Ca2N)(X/Ca2N/X), with X=H or F]. We found that the magnetic moment of the hydrogenated or fluorinated regions promotes the emergence of spin-polarized NFE states confined along the pristine (Ca2N) stripes. Further electronic transport calculations reveal that the (X/Ca2N/X) regions act as spin-dependent scattering centers, spin-filters. We believe that these findings make an important contribution to the development of spintronic devices based on 2D electrides.},
keywords = {},
pubstate = {published},
tppubtype = {workingpaper}
}
@article{PhysRevMaterials.7.104003,
title = {First-principles study of bilayers $mathrmZnX$ and $mathrmCdX$ ($X=mathrmS,mathrmSe,mathrmTe$) direct band-gap semiconductors and their van der Waals heterostructures},
author = {Gabriel Perin and Danilo Kuritza and Rafael Barbosa and Gustavo Tresco and Renato B. Pontes and Roberto H. Miwa and José E. Padilha},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.7.104003},
doi = {10.1103/PhysRevMaterials.7.104003},
year = {2023},
date = {2023-10-01},
urldate = {2023-10-01},
journal = {Phys. Rev. Mater.},
volume = {7},
issue = {10},
pages = {104003},
publisher = {American Physical Society},
abstract = {We conducted comprehensive first-principles investigations of the structural, electronic, and optical properties of hexagonal
Zn
X
and
Cd
X
(
X
=
S
,
Se
,
Te
) and their van der Waals heterostructures. Our results indicate that all materials are thermally and dynamically stable, in contrast to earlier works. Electronic structure calculations with a hybrid functional revealed that the bilayers
Zn
X
and
Cd
X
are characterized by a direct band gap (at the
Γ
point), primarily lies within the visible spectrum of the sunlight (with an exception for ZnS). Moreover, we found the band edges (VBM/CBM of the bilayers) lying below/above the oxidation/reduction potentials (
E
O
2
/
H
2
O
/
E
H
+
/
H
2
) depending on the environment's pH. The effects of mechanical strain on the electronic properties of the bilayers have been thoroughly investigated, revealing an impressive tunability of the band gap, energy position of the band edges, and the ratio of the electron and hole effective masses. The calculated optical absorption spectra showed that the bilayers
Zn
X
and
Cd
X
, with the exception of ZnS, absorb in the visible region. Besides that, we found exciton binding energies between 0.30 and 0.96 eV for ZnTe and CdS bilayers, confirming that the reduced screening effect in 2D systems leads to higher values of exciton binding energies. Furthermore, our results indicated that the ZnTe/CdS heterostructure exhibits a band gap within the visible sunlight spectra. The band edges are located in the bilayer ZnTe resulting in a type-I band offset. However, upon compressive strain, we verified the emergence of the type-II band alignment, as a result, the first absorption peak is redshifted and the exciton exciton wave function spreads out in both materials. Overall, our findings provide valuable insights into the potential of these materials for various technological applications in the fields of the photonics, photocatalysis, and optoelectronics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Zn
X
and
Cd
X
(
X
=
S
,
Se
,
Te
) and their van der Waals heterostructures. Our results indicate that all materials are thermally and dynamically stable, in contrast to earlier works. Electronic structure calculations with a hybrid functional revealed that the bilayers
Zn
X
and
Cd
X
are characterized by a direct band gap (at the
Γ
point), primarily lies within the visible spectrum of the sunlight (with an exception for ZnS). Moreover, we found the band edges (VBM/CBM of the bilayers) lying below/above the oxidation/reduction potentials (
E
O
2
/
H
2
O
/
E
H
+
/
H
2
) depending on the environment’s pH. The effects of mechanical strain on the electronic properties of the bilayers have been thoroughly investigated, revealing an impressive tunability of the band gap, energy position of the band edges, and the ratio of the electron and hole effective masses. The calculated optical absorption spectra showed that the bilayers
Zn
X
and
Cd
X
, with the exception of ZnS, absorb in the visible region. Besides that, we found exciton binding energies between 0.30 and 0.96 eV for ZnTe and CdS bilayers, confirming that the reduced screening effect in 2D systems leads to higher values of exciton binding energies. Furthermore, our results indicated that the ZnTe/CdS heterostructure exhibits a band gap within the visible sunlight spectra. The band edges are located in the bilayer ZnTe resulting in a type-I band offset. However, upon compressive strain, we verified the emergence of the type-II band alignment, as a result, the first absorption peak is redshifted and the exciton exciton wave function spreads out in both materials. Overall, our findings provide valuable insights into the potential of these materials for various technological applications in the fields of the photonics, photocatalysis, and optoelectronics.@article{doi:10.1021/acs.jpcc.3c03123,
title = {Bridging Borophene and Metal Surfaces: Structural, Electronic, and Electron Transport Properties},
author = {Wanderlã L. Scopel and F. Crasto de Lima and Pedro H. Souza and José E. Padilha and Roberto H. Miwa},
url = {https://doi.org/10.1021/acs.jpcc.3c03123},
doi = {10.1021/acs.jpcc.3c03123},
year = {2023},
date = {2023-01-01},
journal = {The Journal of Physical Chemistry C},
volume = {127},
number = {35},
pages = {17556-17566},
abstract = {Currently, solid interfaces composed of two-dimensional materials (2D) in contact with metal surfaces (m-surf) have been the subject of intense research, where the borophene bilayer (BBL) has been considered a prominent material for the development of electronic devices based on 2D platforms. In this work, we present a theoretical study of the energetic, structural, and electronic properties of the BBL/m-surf interface, with m-surf = Ag(111), Au(111), and Al(111) surfaces, and the electronic transport properties of BBL channels connected to the BBL/m-surf top contacts. We find that the BBL becomes metallized due to hybridization with the metal surface states, resulting in Ohmic contacts between BBL and m-surf. However, the projected wavefunctions indicate that the inner and top-most boron layers have a weaker interaction with the m-surf, thus retaining their semiconducting character. The net charge transfers reveal that BBL has become n-type (p-type) doped for m-surf = Ag and Al (= Au). A thorough structural characterization of the BBL/m-surf interface, using a series of simulations of X-ray photoelectron spectra, shows that the formation of the BBL/m-surf interface is characterized by a red shift of the B-1s spectra. Further electronic transport results revealed the emergence of a Schottky barrier between 0.1 and 0.2 eV between the BBL/m-surf contact and the BBL channels. We believe that our findings are timely, bringing important contributions to the applicability of BBLs for developing 2D electronic devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{PhysRevMaterials.7.014001,
title = {Electronic and optical properties of Janus-like hexagonal monolayer materials of group IV-VI},
author = {Rafael Barbosa and Danilo Kuritza and Gabriel Perin and Roberto H. Miwa and R. B. Pontes and José E. Padilha},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.7.014001},
doi = {10.1103/PhysRevMaterials.7.014001},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
journal = {Phys. Rev. Mater.},
volume = {7},
issue = {1},
pages = {014001},
publisher = {American Physical Society},
keywords = {},
pubstate = {published},
tppubtype = {article}
}