Professor José Eduardo Padilha

@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}

}

@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}

}

@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}

}