Professor Roberto Hiroki Miwa

@article{DEOLIVEIRA2024160041,

title = {Unveiling the electronic properties of BiP3 triphosphide from bulk to graphene-based heterostructures by first-principles calculations},

author = {I. S. S. Oliveira and Erika Nascimento Lima and Roberto H. Miwa and Dominike P. Andrade Deus},

url = {https://www.sciencedirect.com/science/article/pii/S0169433224007542},

doi = {https://doi.org/10.1016/j.apsusc.2024.160041},

issn = {0169-4332},

year  = {2024},

date = {2024-04-10},

urldate = {2024-04-10},

journal = {Applied Surface Science},

pages = {160041},

abstract = {In our study, we conduct the structural and electronic properties of bismuth triphosphide (BiP3) in its bulk, few-layer, and monolayer forms. We found that BiP3 in bulk exhibits a metallic stable layered structure. The exfoliation energy of 1.07 J/m2 indicates ease exfoliation, comparable to other triphosphides. The band gap varies with thickness, transitioning from semiconductor—metal between four to five layers, influenced by interlayer coupling and quantum confinement. We also investigated the heterostructure created by depositing graphene (G) on few-layer BiP3. In monolayer (G/m-BiP3) and bilayer (G/2L-BiP3) forms, a metal–semiconductor junction is formed, characterized by weak vdW interactions at the interface and exhibiting p-type Schottky contacts. We observed that the Schottky Barrier Height (SBH) can be modulated by altering the interlayer distance between G and BiP3. This adjustment allows transitions between n-type and p-type Schottky contacts in G/m-BiP3 and the formation of an ohmic contact in G/2L-BiP3. Furthermore, applying an electric field affects the SBH, leading to similar transitions and the development of an ohmic contact. Additionally, our study shows that n-doping in graphene increases with the number of BiP3 layers and external electric field application. These properties position BiP3 few-layer as a promising material for nanoelectronic, optoelectronic, and graphene-based devices.},

keywords = {2D material, First-principles calculations, Graphene interface, Layered materials, Schottky barrier, Triphosphide},

pubstate = {published},

tppubtype = {article}

}

@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{PhysRevApplied.21.034008,

title = {Fe and Co adatoms on bilayer borophene as single-atom catalysts for the oxygen-reduction reaction: A theoretical study},

author = {Walter Orellana and Roberto H. Miwa},

url = {https://link.aps.org/doi/10.1103/PhysRevApplied.21.034008},

doi = {10.1103/PhysRevApplied.21.034008},

year  = {2024},

date = {2024-03-01},

urldate = {2024-03-01},

journal = {Phys. Rev. Appl.},

volume = {21},

issue = {3},

pages = {034008},

publisher = {American Physical Society},

abstract = {This study employs first-principles density-functional-theory (DFT) calculations and ab initio molecular dynamic (AIMD) simulations to investigate the stability, electronic properties, and oxygen-reduction reaction (ORR) activity of M adatoms ( M = Fe , Co ) on free-standing bilayer borophene (BB) with different coverages. Our findings indicate that metals strongly bind to the BB surface, particularly at the hollow sites, inducing metallicity. We analyze the dissociation energy of O 2 and OOH after the adsorption on the metal center of BBM while ORR activity was assessed through the free-energy adsorption of their intermediates. The stability of the systems at electrochemical conditions was investigated by Pourbaix analysis as well as by AIMD simulations, which include explicit solvents. Our results suggest that BBCo in a low-coverage adatom configuration would exhibit competitive ORR activity, with a theoretical overpotential of around 1 V. However, this activity would only be feasible in alkaline environments where the stability BBCo is preserved. Hubbard- U corrections and the hybrid functional approaches within DFT are taken into consideration, and subsequent results are compared.},

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{deus2023unveilingb,

title = {Unveiling the electronic properties of BiP$_3$ triphosphide from bulk to graphene-based heterostructure by first-principles calculations},

author = {Dominike P. Andrade Deus and Igor S. S. Oliveira and Roberto H. Miwa and Erika Nascimento Lima},

url = {https://ui.adsabs.harvard.edu/abs/2023arXiv230902216D/abstract},

doi = { https://doi.org/10.48550/arXiv.2309.02216},

year  = {2023},

date = {2023-09-08},

urldate = {2023-01-01},

abstract = {Triphosphides, with a chemical formula of XP3 (X is a group IIIA, IVA, or VA element), have recently attracted much attention due to their great potential in several applications. Here, using density functional theory calculations, we describe for the first time the structural and electronic properties of the bulk bismuth triphosphide (BiP3). Phonon spectra and molecular dynamics simulations confirm that the 3D crystal of BiP3 is a metal thermodynamically stable with no bandgap. Unlike the bulk, the mono-, bi-, tri-, and tetra-layers of BiP3 are semiconductors with a bandgap ranging from 1.4 to 0.06 eV. However, stackings with more than five layers exhibit metallic behavior equal to the bulk. The results show that quantum confinement is a powerful tool for tuning the electronic properties of BiP3 triphosphide, making it suitable for technological applications. Building on this, the electronic properties of van der Waals heterostructure constructed by graphene (G) and the BiP3 monolayer (m-BiP3) were investigated. Our results show that the Dirac cone in graphene remains intact in this heterostructure. At the equilibrium interlayer distance, the G/m-BiP3 forms an n-type contact with a Schottky barrier height of 0.5 eV. It is worth noting that the SHB in the G/m-BiP3 heterostructure can be adjusted by changing the interlayer distance or applying a transverse electric field. Thus, we show that few-layers BiP3 is an interesting material for realizing nanoelectronic and optoelectronic devices and is an excellent option for designing Schottky nanoelectronic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Deus2023,

title = {Stacking order effects on the energetics and electronic properties of n-doped graphene/h-BN van der Waals heterostructures on SiC(0001)},

author = {Dominike P. de Andrade Deus and João Marcelo J. Lopes and Roberto H. Miwa},

doi = {10.1016/j.carbon.2023.118244},

issn = {0008-6223},

year  = {2023},

date = {2023-09-00},

journal = {Carbon},

volume = {213},

publisher = {Elsevier BV},

keywords = {General Chemistry, General Materials Science},

pubstate = {published},

tppubtype = {article}

}

@article{Aslla-Quispe2023,

title = {Ab initio study of samarium doped barium titanate},

author = {A. P. Aslla-Quispe and G. M. Cruz-Yupanqui and Roberto H. Miwa and J. D. S. Guerra},

doi = {10.1080/00150193.2023.2201765},

issn = {1563-5112},

year  = {2023},

date = {2023-07-27},

urldate = {2023-07-27},

journal = {Ferroelectrics},

volume = {611},

number = {1},

pages = {13--24},

publisher = {Informa UK Limited},

keywords = {Condensed Matter Physics, Electronic, Optical and Magnetic Materials},

pubstate = {published},

tppubtype = {article}

}

@article{CrastodeLima_2023,

title = {Topological insulating phase arising in transition metal dichalcogenide alloy},

author = {F. Crasto de Lima and B Focassio and Roberto H. Miwa and Adalberto Fazzio},

url = {https://dx.doi.org/10.1088/2053-1583/acc670},

doi = {10.1088/2053-1583/acc670},

year  = {2023},

date = {2023-04-01},

urldate = {2023-04-01},

journal = {2D Materials},

volume = {10},

number = {3},

pages = {035001},

publisher = {IOP Publishing},

abstract = {Transition metal dichalcogenides have been the subject of numerous studies addressing technological applications and fundamental issues. Single-layer PtSe2 is a semiconductor with a trivial bandgap, in contrast, its counterpart with of Se atoms substituted by Hg, Pt2HgSe3 (jacutingaite, a naturally occurring mineral) is a 2D topological insulator with a large bandgap. Based on ab-initio calculations, we investigate the energetic stability, and the topological transition in Pt(Hg x Se)2 as a function of alloy concentration, and the distribution of Hg atoms embedded in the PtSe2 host. Our findings reveal the dependence of the topological phase with respect to the alloy concentration and robustness with respect to the distribution of Hg. Through a combination of our ab-initio results and a defect wave function percolation model, we estimate the random alloy concentration threshold for the topological transition to be only . Our results expand the possible search for non-trivial topological phases in random alloy systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Silvestre2023,

title = {Nanoscale structural and electronic properties of cellulose/graphene interfaces},

author = {G. H. Silvestre and F. Crasto de Lima and J. S. Bernardes and Adalberto Fazzio and Roberto H. Miwa},

doi = {10.1039/d2cp04146d},

issn = {1463-9084},

year  = {2023},

date = {2023-01-04},

urldate = {2023-01-04},

journal = {Phys. Chem. Chem. Phys.},

volume = {25},

number = {2},

pages = {1161--1168},

publisher = {Royal Society of Chemistry (RSC)},

abstract = {The development of electronic devices based on the functionalization of (nano)cellulose platforms relies upon an atomistic understanding of the structural and electronic properties of a combined system, cellulose/functional element.},

keywords = {General Physics and Astronomy, Physical and Theoretical Chemistry},

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}

}