| |
Records |
Links |
|
Author |
Bafekry, A.; Yagmurcukardes, M.; Akgenc, B.; Ghergherehchi, M.; Nguyen, C. |
|
| |
Title |
Van der Waals heterostructures of MoS₂ and Janus MoSSe monolayers on graphitic boron-carbon-nitride (BC₃, C₃N, C₃N₄ and C₄N₃) nanosheets: a first-principles study |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Physics D-Applied Physics |
Abbreviated Journal |
J Phys D Appl Phys |
|
| |
Volume |
|
Issue |
|
Pages  |
1-10 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this work, we extensively investigate the structural and electronic properties of van der Waals heterostructures (HTs) constructed by MoS${2}$/$BC3$, MoS${2}$/$C3N$, MoS${2}$/$C3N4$, MoS${2}$/$C4N3$ and those using Janus MoSSe instead of MoS$2$ by performing density functional theory calculations. The electronic band structure calculations and the corresponding partial density of states reveal that the significant changes are driven by quite strong layer-layer interaction between the constitutive layers. Our results show that although all monolayers are semiconductors as free-standing layers, the MoS${2}$/$C3N$ and MoS${2}$/$C4N3$ bilayer HTs display metallic behavior as a consequence of transfer of charge carriers between two constituent layers. In addition, it is found that in MoSSe/$C3N$ bilayer HT, the degree of metallicity is affected by the interface chalcogen atom type when Se atoms are facing to $C3N$ layer, the overlap of the bands around the Fermi level is smaller. Moreover, the half-metallic magnetic $C4N3$ is shown to form magnetic half-metallic trilayer HT with MoS$2$ independent of the stacking sequence, i.e. whether it is sandwiched or two $C4N3$ layer encapsulate MoS$2$ layer. We further analyze the trilayer HTs in which MoS$2$ is encapsulated by two different monolayers and it is revealed that at least with one magnetic monolayer, it is possible to construct a magnetic trilayer. While the trilayer of $C4N3$/MoS${2}$/$BC3$ and $C4N3$/MoS${2}$/$C3N4$ exhibit half-metallic characteristics, $C4N3$/MoS${_2}$/$C3$N possesses a magnetic metallic ground state. Overall, our results reveal that holly structures of BCN crystals are suitable for heterostructure formation even over van der Waals type interaction which significantly changes electronic nature of the constituent layers. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000543344800001 |
Publication Date |
2020-04-07 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-3727 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.4 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 3.4; 2020 IF: 2.588 |
|
| |
Call Number |
UA @ admin @ c:irua:169754 |
Serial |
6651 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A. |
|
| |
Title |
Investigation of the effects of defects and impurities on nanostructures consisting of Group IV and V elements using First-principles calculations |
Type |
Doctoral thesis |
| |
Year |
2020 |
Publication |
|
Abbreviated Journal |
|
|
| |
Volume |
|
Issue |
|
Pages |
126 p. |
|
| |
Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
|
Publication Date |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Additional Links |
UA library record |
|
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:168738 |
Serial |
6554 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Stampfl, C.; Shayesteh, S.F. |
|
| |
Title |
A first-principles study of C3N nanostructures : control and engineering of the electronic and magnetic properties of nanosheets, tubes and ribbons |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Chemphyschem |
Abbreviated Journal |
Chemphyschem |
|
| |
Volume |
21 |
Issue |
2 |
Pages |
164-174 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Using first-principles calculations we systematically investigate the atomic, electronic and magnetic properties of novel two-dimensional materials (2DM) with a stoichiometry C3N which has recently been synthesized. We investigate how the number of layers affect the electronic properties by considering monolayer, bilayer and trilayer structures, with different stacking of the layers. We find that a transition from semiconducting to metallic character occurs which could offer potential applications in future nanoelectronic devices. We also study the affect of width of C3N nanoribbons, as well as the radius and length of C3N nanotubes, on the atomic, electronic and magnetic properties. Our results show that these properties can be modified depending on these dimensions, and depend markedly on the nature of the edge states. Functionalization of the nanostructures by the adsorption of H adatoms is found induce metallic, half-metallic, semiconducting and ferromagnetic behavior, which offers an approach to tailor the properties, as can the application of strain. Our calculations give insight into this new family of C3N nanostructures, which reveal unusual electronic and magnetic properties, and may have great potential in applications such as sensors, electronics and optoelectronic at the nanoscale. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000503453100001 |
Publication Date |
2019-11-09 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1439-4235 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.9 |
Times cited |
27 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 2.9; 2020 IF: 3.075 |
|
| |
Call Number |
UA @ admin @ c:irua:165045 |
Serial |
6282 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Stampfl, C.; Peeters, F.M. |
|
| |
Title |
Dirac half-metallicity of thin PdCl₃ nanosheets : investigation of the effects of external fields, surface adsorption and defect engineering on the electronic and magnetic properties |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
10 |
Issue |
1 |
Pages |
213-215 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
PdCl3 belongs to a novel class of Dirac materials with Dirac spin-gapless semiconducting characteristics. In this paper based, on first-principles calculations, we have systematically investigated the effect of adatom adsorption, vacancy defects, electric field, strain, edge states and layer thickness on the electronic and magnetic properties of PdCl3 (palladium trichloride). Our results show that when spin-orbital coupling is included, PdCl3 exhibits the quantum anomalous Hall effect with a non-trivial band gap of 24 meV. With increasing number of layers, from monolayer to bulk, a transition occurs from a Dirac half-metal to a ferromagnetic metal. On application of a perpendicular electrical field to bilayer PdCl3, we find that the energy band gap decreases with increasing field. Uniaxial and biaxial strain, significantly modifies the electronic structure depending on the strain type and magnitude. Adsorption of adatom and topological defects have a dramatic effect on the electronic and magnetic properties of PdCl3. In particular, the structure can become a metal (Na), half-metal (Be, Ca, Al, Ti, V, Cr, Fe and Cu with, respective, 0.72, 9.71, 7.14, 6.90, 9.71, 4.33 and 9.5 μB magnetic moments), ferromagnetic-metal (Sc, Mn and Co with 4.55, 7.93 and 2.0 μB), spin-glass semiconductor (Mg, Ni with 3.30 and 8.63 μB), and dilute-magnetic semiconductor (Li, K and Zn with 9.0, 9.0 and 5.80 μB magnetic moment, respectively). Single Pd and double Pd + Cl vacancies in PdCl3 display dilute-magnetic semiconductor characteristics, while with a single Cl vacancy, the material becomes a half-metal. The calculated optical properties of PdCl3 suggest it could be a good candidate for microelectronic and optoelectronics devices. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000562795700001 |
Publication Date |
2020-01-14 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.6 |
Times cited |
26 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). We are thankful for comments by Sevil Sarikurt from the department of physics in Dokuz Eylul University. In addition, we acknowledge OpenMX team for OpenMX code. ; |
Approved |
Most recent IF: 4.6; 2020 IF: 4.259 |
|
| |
Call Number |
UA @ admin @ c:irua:169751 |
Serial |
6483 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Yagmurcukardes, M.; Shahrokhi, M.; Ghergherehchi, M. |
|
| |
Title |
Electro-optical properties of monolayer and bilayer boron-doped C₃N: Tunable electronic structure via strain engineering and electric field |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
|
| |
Volume |
168 |
Issue |
|
Pages |
220-229 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this work, the structural, electronic and optical properties of monolayer and bilayer of boron doped C3N are investigated by means of density functional theory-based first-principles calculations. Our results show that with increasing the B dopant concentration from 3.1% to 12.5% in the hexagonal pattern, an indirect-to-direct band gap (0.8 eV) transition occurs. Furthermore, we study the effect of electric field and strain on the B doped C3N bilayer (B-C3N@2L). It is shown that by increasing E-field strength from 0.1 to 0.6V/angstrom, the band gap displays almost a linear decreasing trend, while for the > 0.6V/angstrom, we find dual narrow band gap with of 50 meV (in parallel E-field) and 0.4 eV (in antiparallel E-field). Our results reveal that in-plane and out-of-plane strains can modulate the band gap and band edge positions of the B-C3N@2L. Overall, we predict that B-C3N@2L is a new platform for the study of novel physical properties in layered two-dimensional materials (2DM) which may provide new opportunities to realize high-speed low-dissipation devices. (C) 2020 Elsevier Ltd. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000565900900008 |
Publication Date |
2020-07-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0008-6223 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
10.9 |
Times cited |
21 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government(MSIT) (NRF-2017R1A2B2011989). M. Yagmurcukardes acknowledges Flemish Science Foundation (FWO-VI) by a postdoctoral fellowship. ; |
Approved |
Most recent IF: 10.9; 2020 IF: 6.337 |
|
| |
Call Number |
UA @ admin @ c:irua:171914 |
Serial |
6500 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Stampfl, C.; Ghergherehchi, M.; Shayesteh, S.F. |
|
| |
Title |
A first-principles study of the effects of atom impurities, defects, strain, electric field and layer thickness on the electronic and magnetic properties of the C2N nanosheet |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
|
| |
Volume |
157 |
Issue |
157 |
Pages |
371-384 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Using the first-principles calculations, we explore the structural and novel electronic/optical properties of the C2N nanosheet. To this goal, we systematically investigate the affect of layer thickness, electrical field and strain on the electronic properties of the C2N nanosheet. By increasing the thickness of C2N, we observed that the band gap decreases. Moreover, by applying an electrical field to bilayer C2N, the band gap decreases and a semiconductor-to-metal transition can occur. Our results also confirm that uniaxial and biaxial strain can effectively alter the band gap of C2N monolayer. Furthermore, we show that the electronic and magnetic properties of C2N can be modified by the adsorption and substitution of various atoms. Depending on the species of embedded atoms, they may induce semiconductor (O, C, Si and Be), metal (S, N, P, Na, K, Mg and Ca), dilute-magnetic semiconductor (H, F, B), or ferro-magnetic-metal (Cl, Li) character in C2N monolayer. It was also found that the inclusion of hydrogen or oxygen impurities and nitrogen vacancies, can induce magnetism in the C2N monolayer. These extensive calculations can be useful to guide future studies to modify the electronic/optical properties of two-dimensional materials. (C) 2019 Elsevier Ltd. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000502548500044 |
Publication Date |
2019-10-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0008-6223 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
10.9 |
Times cited |
49 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). We are thankful for comments by Meysam Baghery Tagani from department of physics in University of Guilan and Bohayra Mortazavi from Gottfried Wilhelm Leibniz Universitat Hannover, Hannover, Germany. ; |
Approved |
Most recent IF: 10.9; 2020 IF: 6.337 |
|
| |
Call Number |
UA @ admin @ c:irua:165024 |
Serial |
6283 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Stampfl, C.; Akgenc, B.; Ghergherehchi, M. |
|
| |
Title |
Control of C3N4 and C4N3 carbon nitride nanosheets' electronic and magnetic properties through embedded atoms |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
22 |
Issue |
4 |
Pages |
2249-2261 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In the present work, the effect of various embedded atom impurities on tuning electronic and magnetic properties of C3N4 and C4N3 nanosheets have been studied using first-principles calculations. Our calculations show that C3N4 is a semiconductor and it exhibits extraordinary electronic properties such as dilute-magnetic semiconductor (with H, F, Cl, Be, V, Fe and Co); metal (with N, P, Mg and Ca), half-metal (with Li, Na, K, Al, Sc, Cr, Mn, and Cu) and semiconductor (with O, S, B, C, Si, Ti, Ni and Zn) with the band gaps in the range of 0.3-2.0 eV depending on the species of embedded atom. The calculated electronic properties reveal that C4N3 is a half-metal and it retains half-metallic character with embedded H, O, S, F, B, N, P, Be, Mg, Al, Sc, V, Fe, Ni and Zn atoms. The substitution of Cl, C, Cr and Mn atoms create ferromagnetic-metal character in the C4N3 nanosheet, embedded Co and Cu atoms exhibit a dilute-magnetic semiconductor nature, and embedded Ti atoms result in the system becoming a semiconductor. Therefore, our results reveal the fact that the band gap and magnetism can be modified or induced by various atom impurities, thus, offering effective possibilities to tune the electronic and magnetic properties of C3N4 and C4N3 nanosheets. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000510729400042 |
Publication Date |
2019-12-24 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.3 |
Times cited |
18 |
Open Access |
|
|
| |
Notes |
; This work has supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). B. Akgenc acknowledges financial support the Kirklareli University-BAP under the Project No 189 and TUBITAK ULAKBIM, High Performance and Grid Computing Center. ; |
Approved |
Most recent IF: 3.3; 2020 IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:166553 |
Serial |
6476 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Gogova, D.; M. Fadlallah, M.; V. Chuong, N.; Ghergherehchi, M.; Faraji, M.; Feghhi, S.A.H.; Oskoeian, M. |
|
| |
Title |
Electronic and optical properties of two-dimensional heterostructures and heterojunctions between doped-graphene and C- and N-containing materials |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
23 |
Issue |
8 |
Pages |
4865-4873 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The electronic and optical properties of vertical heterostructures (HTSs) and lateral heterojunctions (HTJs) between (B,N)-codoped graphene (dop@Gr) and graphene (Gr), C3N, BC3 and h-BN monolayers are investigated using van der Waals density functional theory calculations. We have found that all the considered HTSs are energetically and thermally feasible at room temperature, and therefore they can be synthesized experimentally. The dop@Gr/Gr, BC3/dop@Gr and BN/dop@Gr HTSs are semiconductors with direct bandgaps of 0.1 eV, 80 meV and 1.23 eV, respectively, while the C3N/dop@Gr is a metal because of the strong interaction between dop@Gr and C3N layers. On the other hand, the dop@Gr-Gr and BN-dop@Gr HTJs are semiconductors, whereas the C3N-dop@Gr and BC3-dop@Gr HTJs are metals. The proposed HTSs can enhance the absorption of light in the whole wavelength range as compared to Gr and BN monolayers. The applied electric field or pressure strain changes the bandgaps of the HTSs and HTJs, indicating that these HTSs are highly promising for application in nanoscale multifunctional devices. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000625306100038 |
Publication Date |
2021-02-05 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:177659 |
Serial |
6986 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Stampfl, C.; Akgenc, B.; Mortazavi, B.; Ghergherehchi, M.; Nguyen, C.V. |
|
| |
Title |
Embedding of atoms into the nanopore sites of the C₆N₆ and C₆N₈ porous carbon nitride monolayers with tunable electronic properties |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
22 |
Issue |
11 |
Pages |
6418-6433 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Using first-principles calculations, we study the effect of embedding various atoms into the nanopore sites of both C6N6 and C6N8 monolayers. Our results indicate that the embedded atoms significantly affect the electronic and magnetic properties of C6N6 and C6N8 monolayers and lead to extraordinary and multifarious electronic properties, such as metallic, half-metallic, spin-glass semiconductor and dilute-magnetic semiconductor behaviour. Our results reveal that the H atom concentration dramatically affects the C6N6 monolayer. On increasing the H coverage, the impurity states also increase due to H atoms around the Fermi-level. C6N6 shows metallic character when the H atom concentration reaches 6.25%. Moreover, the effect of charge on the electronic properties of both Cr@C6N6 and C@C6N8 is also studied. Cr@C6N6 is a ferromagnetic metal with a magnetic moment of 2.40 mu(B), and when 0.2 electrons are added and removed, it remains a ferromagnetic metal with a magnetic moment of 2.57 and 2.77 mu(B), respectively. Interestingly, one can observe a semi-metal, in which the VBM and CBM in both spin channels touch each other near the Fermi-level. C@C6N8 is a semiconductor with a nontrivial band gap. When 0.2 electrons are removed, it remains metallic, and under excess electronic charge, it exhibits half-metallic behaviour. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000523409400037 |
Publication Date |
2020-02-20 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.3 |
Times cited |
17 |
Open Access |
|
|
| |
Notes |
; This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2017R1A2B2011989). ; |
Approved |
Most recent IF: 3.3; 2020 IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:168617 |
Serial |
6504 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Faraji, M.; Ziabari, A.A.; Fadlallah, M.M.; Nguyen, C., V; Ghergherehchi, M.; Feghhi, S.A.H. |
|
| |
Title |
A van der Waals heterostructure of MoS₂/MoSi₂N₄ : a first-principles study |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
New Journal Of Chemistry |
Abbreviated Journal |
New J Chem |
|
| |
Volume |
45 |
Issue |
18 |
Pages |
8291-8296 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Motivated by the successful preparation of MoSi2N4 monolayers in the last year [Y.-L. Hong et al., Science, 2020, 369, 670-674], we investigate the structural, electronic and optical properties of the MoS2/MoSi2N4 heterostructure (HTS). The phonon dispersion and the binding energy calculations refer to the stability of the HTS. The heterostructure has an indirect bandgap of 1.26 (1.84) eV using PBE (HSE06) which is smaller than the corresponding value of MoSi2N4 and MoS2 monolayers. We find that the work function of the MoS2/MoSi2N4 HTS is smaller than the corresponding value of its individual monolayers. The heterostructure structure can enhance the absorption of light spectra not only in the ultraviolet region but also in the visible region as compared to MoSi2N4 and MoS2 monolayers. The refractive index behaviour of the HTS can be described as the cumulative effect which is well described in terms of a combination of the individual effects (the refractive index of MoSi2N4 and MoS2 monolayers). |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000642436200001 |
Publication Date |
2021-03-10 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1144-0546 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.269 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.269 |
|
| |
Call Number |
UA @ admin @ c:irua:178300 |
Serial |
6964 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Faraji, M.; Bafekry, A.; Gogova, D.; Hoat, D.M.; Ghergherehchi, M.; Chuong, N.V.; Feghhi, S.A.H. |
|
| |
Title |
Novel two-dimensional ZnO₂, CdO₂ and HgO₂ monolayers: a first-principles-based prediction |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
New Journal Of Chemistry |
Abbreviated Journal |
New J Chem |
|
| |
Volume |
45 |
Issue |
|
Pages |
9368-9374 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this paper, the existence of monolayers with the chemical formula XO2, where X = Zn, Cd, and Hg with hexagonal and tetragonal lattice structures is theoretically predicted by means of first principles calculations. Through cohesive energy calculation and phonon dispersion simulation, it has been proven that the two-dimensional XO2 monolayers proposed are energetically and dynamically stable suggesting their potential experimental realization. Our detailed study demonstrates that these novel newly predicted materials are half-metals and dilute magnetic semiconductors, and they exhibit magnetism in the ground state. The half-metallic character could find many applications in electronic and spintronic devices. Research into the magnetic properties revealed here can enrich theoretical knowledge in this area and provide more potential candidates for XO2 2D-based materials and van der Waals heterostructures. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000645671700001 |
Publication Date |
2021-04-16 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1144-0546 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.269 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.269 |
|
| |
Call Number |
UA @ admin @ c:irua:178245 |
Serial |
7006 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Shahrokhi, M.; Shafique, A.; Jappor, H.R.; Fadlallah, M.M.; Stampfl, C.; Ghergherehchi, M.; Mushtaq, M.; Feghhi, S.A.H.; Gogova, D. |
|
| |
Title |
Semiconducting chalcogenide alloys based on the (Ge, Sn, Pb) (S, Se, Te) formula with outstanding properties : a first-principles calculation study |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
ACS Omega |
Abbreviated Journal |
|
|
| |
Volume |
6 |
Issue |
14 |
Pages |
9433-9441 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Very recently, a new class of the multicationic and -anionic entropy-stabilized chalcogenide alloys based on the (Ge, Sn, Pb) (S, Se, Te) formula has been successfully fabricated and characterized experimentally [Zihao Deng et al., Chem. Mater. 32, 6070 (2020)]. Motivated by the recent experiment, herein, we perform density functional theory-based first-principles calculations in order to investigate the structural, mechanical, electronic, optical, and thermoelectric properties. The calculations of the cohesive energy and elasticity parameters indicate that the alloy is stable. Also, the mechanical study shows that the alloy has a brittle nature. The GeSnPbSSeTe alloy is a semiconductor with a direct band gap of 0.4 eV (0.3 eV using spin-orbit coupling effect). The optical analysis illustrates that the first peak of Im(epsilon) for the GeSnPbSSeTe alloy along all polarization directions is located in the visible range of the spectrum which renders it a promising material for applications in optical and electronic devices. Interestingly, we find an optically anisotropic character of this system which is highly desirable for the design of polarization-sensitive photodetectors. We have accurately predicted the thermoelectric coefficients and have calculated a large power factor value of 3.7 x 10(11) W m(-1) K-2 s(-1) for p-type. The high p-type power factor is originated from the multiple valleys near the valence band maxima. The anisotropic results of the optical and transport properties are related to the specific tetragonal alloy unit cell. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000640649500012 |
Publication Date |
2021-03-30 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2470-1343 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:178395 |
Serial |
7017 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Mortazavi, B.; Faraji, M.; Shahrokhi, M.; Shafique, A.; Jappor, H.R.; Nguyen, C.; Ghergherehchi, M.; Feghhi, S.A.H. |
|
| |
Title |
Ab initio prediction of semiconductivity in a novel two-dimensional Sb₂X₃ (X= S, Se, Te) monolayers with orthorhombic structure |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Scientific Reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
11 |
Issue |
1 |
Pages |
10366 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Sb2S3 and Sb2Se3 are well-known layered bulk structures with weak van der Waals interactions. In this work we explore the atomic lattice, dynamical stability, electronic and optical properties of Sb2S3, Sb2Se3 and Sb2Te3 monolayers using the density functional theory simulations. Molecular dynamics and phonon dispersion results show the desirable thermal and dynamical stability of studied nanosheets. On the basis of HSE06 and PBE/GGA functionals, we show that all the considered novel monolayers are semiconductors. Using the HSE06 functional the electronic bandgap of Sb2S3, Sb2Se3 and Sb2Te3 monolayers are predicted to be 2.15, 1.35 and 1.37 eV, respectively. Optical simulations show that the first absorption coefficient peak for Sb2S3, Sb2Se3 and Sb2Te3 monolayers along in-plane polarization is suitable for the absorption of the visible and IR range of light. Interestingly, optically anisotropic character along planar directions can be desirable for polarization-sensitive photodetectors. Furthermore, we systematically investigate the electrical transport properties with combined first-principles and Boltzmann transport theory calculations. At optimal doping concentration, we found the considerable larger power factor values of 2.69, 4.91, and 5.45 for hole-doped Sb2S3, Sb2Se3, and Sb2Te3, respectively. This study highlights the bright prospect for the application of Sb2S3, Sb2Se3 and Sb2Te3 nanosheets in novel electronic, optical and energy conversion systems. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000656961400019 |
Publication Date |
2021-05-14 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.259 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.259 |
|
| |
Call Number |
UA @ admin @ c:irua:179188 |
Serial |
6965 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Ghergherehchi, M.; Shayesteh, S.F. |
|
| |
Title |
Tuning the electronic and magnetic properties of antimonene nanosheets via point defects and external fields: first-principles calculations |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
21 |
Issue |
20 |
Pages |
10552-10566 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Defects are inevitably present in materials, and their existence in a material strongly affects its fundamental physical properties. We have systematically investigated the effects of surface adsorption, substitutional impurities, defect engineering, an electric field and strain engineering on the structural, electronic and magnetic properties of antimonene nanosheets, using spin-polarized density functional calculations based on first-principles. The adsorption or substitution of atoms can locally modify the atomic and electronic structures as well as induce a variety of electronic behaviors including metal, half-metal, ferromagnetic metal, dilute magnetic semiconductor and spin-glass semiconductor. Our calculations show that the presence of typical defects (vacancies and Stone-Wales defect) in antimonene affects the geometrical symmetry as well as the band gap in the electronic band structure and induces magnetism to antimonene. Moreover, by applying an external electric field and strain (uniaxial and biaxial), the electronic structure of antimonene can be easily modified. The calculation results presented in this paper provide a fundamental insight into the tunable nature of the electronic properties of antimonene, supporting its promise for use in future applications. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000476561000031 |
Publication Date |
2019-04-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
17 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:161945 |
Serial |
5430 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Naseri, M.; Bafekry, A.; Faraji, M.; Hoat, D.M.; Fadlallah, M.M.; Ghergherehchi, M.; Sabbaghi, N.; Gogova, D. |
|
| |
Title |
Two-dimensional buckled tetragonal cadmium chalcogenides including CdS, CdSe, and CdTe monolayers as photo-catalysts for water splitting |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
23 |
Issue |
21 |
Pages |
12226-12232 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Pure hydrogen production via water splitting is an ideal strategy for producing clean and sustainable energy. Two-dimensional (2D) cadmium chalcogenide single-layers with a tetragonal crystal structure, namely Tetra-CdX (X = S, Se, and Te) monolayers, are theoretically predicted by means of density functional theory (DFT). Their structural stability and electronic and optical properties are investigated. We find that Tetra-CdX single-layers are thermodynamically stable. Their stability decreases as we go down the 6A group in the periodic table, i.e., from X = S to Se, and Te which also means that the electronegativity decreases. All considered novel monolayers are indirect band gap semiconductors. Using the HSE06 functional the electronic band gaps of CdS, CdSe, and CdTe monolayers are predicted to be 3.10 eV, 2.97 eV, and 2.90 eV, respectively. The impact of mechanical strain on the physical properties was studied, which indicates that compressive strain increases the band gap and tensile strain decreases the band gap. The optical properties of the Tetra-CdX monolayers show the ability of these monolayers to absorb visible light. Due to the suitable band gaps and band edge positions of Tetra-CdX, these newly discovered 2D materials are promising for photocatalytic water splitting. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000651904600001 |
Publication Date |
2021-04-30 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:178378 |
Serial |
7041 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Yagmurcukardes, M.; Akgenc, B.; Ghergherehchi, M.; Mortazavi, B. |
|
| |
Title |
First-principles investigation of electronic, mechanical and thermoelectric properties of graphene-like XBi (X = Si, Ge, Sn) monolayers |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
23 |
Issue |
21 |
Pages |
12471-12478 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Research progress on single layer group III monochalcogenides has been increasing rapidly owing to their interesting physics. Herein, we investigate the dynamically stable single layer forms of XBi (X = Ge, Si or Sn) using density functional theory calculations. Phonon band dispersion calculations and ab initio molecular dynamics simulations reveal the dynamical and thermal stability of the considered monolayers. Raman spectra calculations indicate the existence of 5 Raman active phonon modes, 3 of which are prominent and can be observed in possible Raman measurements. The electronic band structures of the XBi single layers were investigated with and without the effects of spin-orbit coupling (SOC). Our results show that XBi single layers show semiconducting properties with narrow band gap values without SOC. However, only single layer SiBi is an indirect band gap semiconductor, while GeBi and SnBi exhibit metallic behaviors when adding spin-orbit coupling effects. In addition, the calculated linear elastic parameters indicate the soft nature of the predicted monolayers. Moreover, our predictions for the thermoelectric properties of single layer XBi reveal that SiBi is a good thermoelectric material with increasing temperature. Overall, it is proposed that single layer XBi structures can be alternative, stable 2D single layers with varying electronic and thermoelectric properties. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000653851100001 |
Publication Date |
2021-04-08 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:179007 |
Serial |
6992 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Shayesteh, S.F.; Peeters, F.M. |
|
| |
Title |
C3N Monolayer: Exploring the Emerging of Novel Electronic and Magnetic Properties with Adatom Adsorption, Functionalizations, Electric Field, Charging, and Strain |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
123 |
Issue |
19 |
Pages |
12485-12499 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Two-dimensional polyaniline with structural unit C3N is an indirect semiconductor with 0.4 eV band gap, which has attracted a lot of interest because of its unusual electronic, optoelectronic, thermal, and mechanical properties useful for various applications. Adsorption of adatoms is an effective method to improve and tune the properties of C3N. Using first-principles calculations, we investigated the adsorption of adatoms, including H, O, S, F, Cl, B, C, Si, N, P, Al, Li, Na, K, Be, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, on C3N. Depending on the adatom size and the number of valence electrons, they may induce metallic, half-metallic, semiconducting, and ferromagnetic-metallic behavior. In addition, we investigate the effects of an electrical field, charging, and strain on C3N and found how the electronic and magnetic properties are modified. Semi- and full hydrogenation are studied. From the mechanical and thermal stability of C3N monolayer, we found it to be a hard material that can withstand large strain. From our calculations, we gained novel insights into the properties of C3N demonstrating its unique electronic and magnetic properties that can be useful for semiconducting, nanosensor, and catalytic applications. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000468368800053 |
Publication Date |
2019-04-24 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.536 |
Times cited |
67 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FW0-V1). The authors thank Keyvan Nazifi from the Cluster Center of Faculty of Science, Guilan University, for his help. They acknowledge OpenMX team for OpenMX code. ; |
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
UA @ admin @ c:irua:160323 |
Serial |
5196 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Mortazavi, B.; Ziabari, A.A.; Khatibani, A.B.; Nguyen, C., V; Ghergherehchi, M.; Gogova, D. |
|
| |
Title |
Point defects in a two-dimensional ZnSnN₂ nanosheet : a first-principles study on the electronic and magnetic properties |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
125 |
Issue |
23 |
Pages |
13067-13075 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The reduction of dimensionality is a very effective way to achieve appealing properties in two-dimensional materials (2DMs). First-principles calculations can greatly facilitate the prediction of 2DM properties and find possible approaches to enhance their performance. We employed first-principles calculations to gain insight into the impact of different types of point defects (vacancies and substitutional dopants) on the electronic and magnetic properties of a ZnSnN2 (ZSN) monolayer. We show that Zn, Sn, and N + Zn vacancy-defected structures are p-type conducting, while the defected ZSN with a N vacancy is n-type conducting. For substitutional dopants, we found that all doped structures are thermally and energetically stable. The most stable structure is found to be B-doping at the Zn site. The highest work function value (5.0 eV) has been obtained for Be substitution at the Sn site. Li-doping (at the Zn site) and Be-doping (at the Sn site) are p-type conducting, while B-doping (at the Zn site) is n-type conducting. We found that the considered ZSN monolayer-based structures with point defects are magnetic, except those with the N vacancy defects and Be-doped structures. The ab initio molecular dynamics simulations confirm that all substitutionally doped and defected structures are thermally stable. Thus, our results highlight the possibility of tuning the magnetism in ZnSnN2 monolayers through defect engineering. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000664312500063 |
Publication Date |
2021-06-03 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.536 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
UA @ admin @ c:irua:179741 |
Serial |
7012 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Obeid, M.; Nguyen, C.; Bagheri Tagani, M.; Ghergherehchi, M. |
|
| |
Title |
Graphene hetero-multilayer on layered platinum mineral Jacutingaite (Pt₂HgSe₃): Van der Waals heterostructures with novel optoelectronic and thermoelectric performances |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Materials Chemistry A |
Abbreviated Journal |
J Mater Chem A |
|
| |
Volume |
8 |
Issue |
26 |
Pages |
13248-13260 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Motivated by the recent successful synthesis of the layered platinum mineral jacutingaite (Pt2HgSe3), we have studied the optoelectronic, mechanical, and thermoelectric properties of graphene hetero-multilayer on Pt(2)HgSe(3)monolayer (PHS) heterostructures (LG/PHS) by using first-principles calculations. PHS is a topological insulator with a band gap of about 160 meV with fully relativistic calculations; when graphene layers are stacked on PHS, a narrow band gap of similar to 10-15 meV opens. In the presence of gate-voltage and out-of plane strain,i.e.pressure, the electronic properties are modified; the Dirac-cone of graphene can be shifted upwards (downward) to a lower (higher) binding energy. The absorption spectrum shows two peaks, which are located around 216 nm (5.74 eV) and protracted to 490 nm (2.53 eV), indicating that PHS could absorb more visible light. Increasing the number of graphene layers on PHS has a positive impact on the UV-vis light absorption and gives a clear red-shift with enhanced absorption intensity. To investigate the electronic performance of the heterostructure, the electrical conductance and thermopower of a device composed of graphene layers and PHS is examined by a combination of DFT and Green function formalism. The number of graphene layers can significantly tune the thermopower and electrical conductance. This analysis reveals that the heterostructures not only significantly affect the electronic properties, but they can also be used as an efficient way to modulate the optic and thermoelectric properties. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000546391600032 |
Publication Date |
2020-05-28 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2050-7488; 2050-7496 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
11.9 |
Times cited |
20 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (NRF-2017R1A2B2011989) and Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 103.01-2019.05. ; |
Approved |
Most recent IF: 11.9; 2020 IF: 8.867 |
|
| |
Call Number |
UA @ admin @ c:irua:169755 |
Serial |
6529 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Karbasizadeh, S.; Stampfl, C.; Faraji, M.; Hoat, D.M.; Sarsari, I.A.; Feghhi, S.A.H.; Ghergherehchi, M. |
|
| |
Title |
Two-dimensional Janus semiconductor BiTeCl and BiTeBr monolayers : a first-principles study on their tunable electronic properties via an electric field and mechanical strain |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
23 |
Issue |
28 |
Pages |
15216-15223 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Motivated by the recent successful synthesis of highly crystalline ultrathin BiTeCl and BiTeBr layered sheets [Debarati Hajra et al., ACS Nano, 2020, 14, 15626], herein for the first time, we carry out a comprehensive study on the structural and electronic properties of BiTeCl and BiTeBr Janus monolayers using density functional theory (DFT) calculations. Different structural and electronic parameters including the lattice constant, bond lengths, layer thickness in the z-direction, different interatomic angles, work function, charge density difference, cohesive energy and Rashba coefficients are determined to acquire a deep understanding of these monolayers. The calculations show good stability of the studied single layers. BiTeCl and BiTeBr monolayers are semiconductors with electronic bandgaps of 0.83 and 0.80 eV, respectively. The results also show that the semiconductor-metal transformation can be induced by increasing the number of layers. In addition, the engineering of the electronic structure is also studied by applying an electric field, and mechanical uniaxial and biaxial strain. The results show a significant change of the bandgaps and that an indirect-direct band-gap transition can be induced. This study highlights the positive prospect for the application of BiTeCl and BiTeBr layered sheets in novel electronic and energy conversion systems. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000670553900001 |
Publication Date |
2021-06-16 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:179827 |
Serial |
7042 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Faraji, M.; Bafekry, A.; Fadlallah, M.M.; Molaei, F.; Hieu, N.N.; Qian, P.; Ghergherehchi, M.; Gogova, D. |
|
| |
Title |
Surface modification of titanium carbide MXene monolayers (Ti₂C and Ti₃C₂) via chalcogenide and halogenide atoms |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
23 |
Issue |
28 |
Pages |
15319-15328 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Inspired by the recent successful growth of Ti2C and Ti3C2 monolayers, here, we investigate the structural, electronic, and mechanical properties of functionalized Ti2C and Ti3C2 monolayers by means of density functional theory calculations. The results reveal that monolayers of Ti2C and Ti3C2 are dynamically stable metals. Phonon band dispersion calculations demonstrate that two-surface functionalization of Ti2C and Ti(3)C(2)via chalcogenides (S, Se, and Te), halides (F, Cl, Br, and I), and oxygen atoms results in dynamically stable novel functionalized monolayer materials. Electronic band dispersions and density of states calculations reveal that all functionalized monolayer structures preserve the metallic nature of both Ti2C and Ti3C2 except Ti2C-O-2, which possesses the behavior of an indirect semiconductor via full-surface oxygen passivation. In addition, it is shown that although halide passivated Ti3C2 structures are still metallic, there exist multiple Dirac-like cones around the Fermi energy level, which indicates that semi-metallic behavior can be obtained upon external effects by tuning the energy of the Dirac cones. In addition, the computed linear-elastic parameters prove that functionalization is a powerful tool in tuning the mechanical properties of stiff monolayers of bare Ti2C and Ti3C2. Our study discloses that the electronic and structural properties of Ti2C and Ti3C2 MXene monolayers are suitable for surface modification, which is highly desirable for material property engineering and device integration. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000672406800001 |
Publication Date |
2021-06-23 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:179809 |
Serial |
7027 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Obeid, M.M.; Stampfl, C.; Bafekry, A.; Guan, Z.; Jappor, H.R.; Nguyen, C., V; Naseri, M.; Hoat, D.M.; Hieu, N.N.; Krauklis, A.E.; Tuan V Vu; Gogova, D. |
|
| |
Title |
First-principles investigation of nonmetal doped single-layer BiOBr as a potential photocatalyst with a low recombination rate |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
22 |
Issue |
27 |
Pages |
15354-15364 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Nonmetal doping is an effective approach to modify the electronic band structure and enhance the photocatalytic performance of bismuth oxyhalides. Using density functional theory, we systematically examine the fundamental properties of single-layer BiOBr doped with boron (B) and phosphorus (P) atoms. The stability of the doped models is investigated based on the formation energies, where the substitutional doping is found to be energetically more stable under O-rich conditions than under Bi-rich ones. The results showed that substitutional doping of P atoms reduced the bandgap of pristine BiOBr to a greater extent than that of boron substitution. The calculation of the effective masses reveals that B doping can render the electrons and holes of pristine BiOBr lighter and heavier, respectively, resulting in a slower recombination rate of photoexcited electron-hole pairs. Based on the results of HOMO-LUMO calculations, the introduction of B atoms tends to increase the number of photocatalytically active sites. The top of the valence band and the conduction band bottom of the B doped BiOBr monolayer match well with the water redox potentials in an acidic environment. The absorption spectra propose that B(P) doping causes a red-shift. Overall, the results predict that nonmetal-doped BiOBr monolayers have a reduced bandgap, a slow recombination rate, more catalytically active sites, enhanced optical absorption edges, and reduced work functions, which will contribute to superior photocatalytic performance. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000549894000018 |
Publication Date |
2020-06-16 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.3 |
Times cited |
18 |
Open Access |
|
|
| |
Notes |
; This work was partially supported by the financial support from the Natural Science Foundation of China (Grant No. 11904203) and the Fundamental Research Funds of Shandong University (Grant No. 2019GN065). ; |
Approved |
Most recent IF: 3.3; 2020 IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:171235 |
Serial |
6522 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Nguyen, C.; Obeid, M.M.; Ghergherehchi, M. |
|
| |
Title |
Modulating the electro-optical properties of doped C₃N monolayers and graphene bilayersviamechanical strain and pressure |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
New Journal Of Chemistry |
Abbreviated Journal |
New J Chem |
|
| |
Volume |
44 |
Issue |
36 |
Pages |
15785-15792 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this work, we investigated systematically the electronic and optical properties of B doped C3N monolayers as well as B and N doped graphene bilayers (BN-Gr@2L). We found that the doping of B atoms leads to an enlarged band gap of the C3N monolayer and when the dopant concentration reaches 12.5%, an indirect-to-direct band gap switching occurs. In addition, with co-doping of B and N atoms on the graphene monolayer in the hexagonal configuration, an electronic transition from semi-metal to semiconductor occurs. Our optical results for B-C3N show a broad absorption spectrum in a wide visible range starting from 400 nm to 1000 nm with strong absorption intensity, making it a suitable candidate for nanoelectronic and optoelectronic applications. Interestingly, a transition from semi-metal to semiconductor emerges in the graphene monolayer with doping of B and N atoms. Furthermore, our results demonstrate that the in-plane strain and out-of-plane strain (pressure) can modulate the band gap of the BN-Gr@2L. The controllable electronic properties and optical features of the doped graphene bilayer by strain engineering may facilitate their practical performance for various applications in future. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000571972400054 |
Publication Date |
2020-08-18 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1144-0546 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.3 |
Times cited |
7 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2017R1A2B2011989). ; |
Approved |
Most recent IF: 3.3; 2020 IF: 3.269 |
|
| |
Call Number |
UA @ admin @ c:irua:171936 |
Serial |
6561 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Jappor, H.R.; Karbasizadeh, S.; Ghergherehchi, M.; Sarsari, I.A.; Ziabari, A.A. |
|
| |
Title |
Novel two-dimensional AlSb and InSb monolayers with a double-layer honeycomb structure : a first-principles study |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Chemistry Chemical Physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
23 |
Issue |
34 |
Pages |
18752-18759 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this work, motivated by the fabrication of an AlSb monolayer, we have focused on the electronic, mechanical and optical properties of AlSb and InSb monolayers with double-layer honeycomb structures, employing the density functional theory approach. The phonon band structure and cohesive energy confirm the stability of the XSb (X = Al and In) monolayers. The mechanical properties reveal that the XSb monolayers have a brittle nature. Using the GGA + SOC (HSE + SOC) functionals, the bandgap of the AlSb monolayer is predicted to be direct, while InSb has a metallic character using both functionals. We find that XSb (X = Al, In) two-dimensional bodies can absorb ultraviolet light. The present findings suggest several applications of AlSb and InSb monolayers in novel optical and electronic usages. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000686236800001 |
Publication Date |
2021-08-05 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:181712 |
Serial |
7005 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Shayesteh, S.F.; Peeters, F.M. |
|
| |
Title |
Introducing novel electronic and magnetic properties in C3N nanosheets by defect engineering and atom substitution |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
21 |
Issue |
37 |
Pages |
21070-21083 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Using first-principles calculations the effect of topological defects, vacancies, Stone-Wales and anti-site and substitution of atoms, on the structure and electronic properties of monolayer C3N are investigated. Vacancy defects introduce localized states near the Fermi level and a local magnetic moment. While pristine C3N is an indirect semiconductor with a 0.4 eV band gap, with substitution of O, S and Si atoms for C, it remains a semiconductor with a band gap in the range 0.25-0.75 eV, while it turns into a metal with H, Cl, B, P, Li, Na, K, Be and Mg substitution. With F substitution, it becomes a dilute-magnetic semiconductor, while with Ca substitution it is a ferromagnetic-metal. When replacing the N host atom, C3N turns into: a metal (H, O, S, C, Si, P, Li and Be), ferromagnetic-metal (Mg), half-metal (Ca) and spin-glass semiconductor (Na and K). Moreover, the effects of charging and strain on the electronic properties of Na atom substitution in C3N are investigated. We found that the magnetic moment decreases or increases depending on the type and size of strain (tensile or compression). Our study shows how the band gap and magnetism in monolayer C3N can be tuned by introducing defects and atom substitution. The so engineered C3N can be a good candidate for future low dimensional devices. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000489984200050 |
Publication Date |
2019-09-09 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.123 |
Times cited |
52 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
UA @ admin @ c:irua:163732 |
Serial |
5418 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Nguyen, C., V; Goudarzi, A.; Ghergherehchi, M.; Shafieirad, M. |
|
| |
Title |
Investigation of strain and doping on the electronic properties of single layers of C₆N₆ and C₆N₈: a first principles study |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Rsc Advances |
Abbreviated Journal |
Rsc Adv |
|
| |
Volume |
10 |
Issue |
46 |
Pages |
27743-27751 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this work, by performing first-principles calculations, we explore the effects of various atom impurities on the electronic and magnetic properties of single layers of C(6)N(6)and C6N8. Our results indicate that atom doping may significantly modify the electronic properties. Surprisingly, doping Cr into a holey site of C(6)N(6)monolayer was found to exhibit a narrow band gap of 125 meV upon compression strain, considering the spin-orbit coupling effect. Also, a C atom doped in C(6)N(8)monolayer shows semi-metal nature under compression strains larger than -2%. Our results propose that Mg or Ca doped into strained C(6)N(6)may exhibit small band gaps in the range of 10-30 meV. In addition, a magnetic-to-nonmagnetic phase transition can occur under large tensile strains in the Ca doped C(6)N(8)monolayer. Our results highlight the electronic properties and magnetism of C(6)N(6)and C(6)N(8)monolayers. Our results show that the electronic properties can be effectively modified by atom doping and mechanical strain, thereby offering new possibilities to tailor the electronic and magnetic properties of C(6)N(6)and C(6)N(8)carbon nitride monolayers. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000553911800053 |
Publication Date |
2020-07-24 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.9 |
Times cited |
11 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2017R1A2B2011989). ; |
Approved |
Most recent IF: 3.9; 2020 IF: 3.108 |
|
| |
Call Number |
UA @ admin @ c:irua:172111 |
Serial |
6553 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Shojai, F.; Hoat, D.M.; Shahrokhi, M.; Ghergherehchi, M.; Nguyen, C. |
|
| |
Title |
The mechanical, electronic, optical and thermoelectric properties of two-dimensional honeycomb-like of XSb (X = Si, Ge, Sn) monolayers: a first-principles calculations |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Rsc Advances |
Abbreviated Journal |
Rsc Adv |
|
| |
Volume |
10 |
Issue |
51 |
Pages |
30398-30405 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Herein, by using first-principles calculations, we demonstrate a two-dimensional (2D) of XSb (X = Si, Ge, and Sn) monolayers that have a honey-like crystal structure. The structural, mechanical, electronic, thermoelectric efficiency, and optical properties of XSb monolayers are studied.Ab initiomolecular dynamic simulations and phonon dispersion calculations suggests their good thermal and dynamical stabilities. The mechanical properties of XSb monolayers shows that the monolayers are considerably softer than graphene, and their in-plane stiffness decreases from SiSb to SnSb. Our results shows that the single layers of SiSb, GeSb and SnSb are semiconductor with band gap of 1.48, 0.77 and 0.73 eV, respectively. The optical analysis illustrate that the first absorption peaks of the SiSb, GeSb and SnSb monolayers along the in-plane polarization are located in visible range of light which may serve as a promising candidate to design advanced optoelectronic devices. Thermoelectric properties of the XSb monolayers, including Seebeck coefficient, electrical conductivity, electronic thermal conductivity, power factor and figure of merit are calculated as a function of doping level at temperatures of 300 K and 800 K. Between the studied two-dimensional materials (2DM), SiSb single layer may be the most promising candidate for application in the thermoelectric generators. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000561344000009 |
Publication Date |
2020-08-17 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.9 |
Times cited |
2 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). ; |
Approved |
Most recent IF: 3.9; 2020 IF: 3.108 |
|
| |
Call Number |
UA @ admin @ c:irua:172074 |
Serial |
6624 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Shojaei, F.; Obeid, M.M.; Ghergherehchi, M.; Nguyen, C.; Oskouian, M. |
|
| |
Title |
Two-dimensional silicon bismotide (SiBi) monolayer with a honeycomb-like lattice: first-principles study of tuning the electronic properties |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Rsc Advances |
Abbreviated Journal |
Rsc Adv |
|
| |
Volume |
10 |
Issue |
53 |
Pages |
31894-31900 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Using density functional theory, we investigate a novel two-dimensional silicon bismotide (SiBi) that has a layered GaSe-like crystal structure.Ab initiomolecular dynamic simulations and phonon dispersion calculations suggest its good thermal and dynamical stability. The SiBi monolayer is a semiconductor with a narrow indirect bandgap of 0.4 eV. Our results show that the indirect bandgap decreases as the number of layers increases, and when the number of layers is more than six layers, direct-to-indirect bandgap switching occurs. The SiBi bilayer is found to be very sensitive to an E-field. The bandgap monotonically decreases in response to uniaxial and biaxial compressive strain, and reaches 0.2 eV at 5%, while at 6%, the semiconductor becomes a metal. For both uniaxial and biaxial tensile strains, the material remains a semiconductor and indirect-to-direct bandgap transition occurs at a strain of 3%. Compared to a SiBi monolayer with a layer thickness of 4.89 angstrom, the bandgap decreases with either increasing or decreasing layer thickness, and at a thicknesses of 4.59 to 5.01 angstrom, the semiconductor-to-metal transition happens. In addition, under pressure, the semiconducting character of the SiBi bilayer with a 0.25 eV direct bandgap is preserved. Our results demonstrate that the SiBi nanosheet is a promising candidate for designing high-speed low-dissipation devices. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000565206400027 |
Publication Date |
2020-09-02 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.9 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant, funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). ; |
Approved |
Most recent IF: 3.9; 2020 IF: 3.108 |
|
| |
Call Number |
UA @ admin @ c:irua:172045 |
Serial |
6644 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Nguyen, H.T.T.; Obeid, M.M.; Bafekry, A.; Idrees, M.; Vu, T.V.; Phuc, H., V; Hieu, N.N.; Le Hoa, T.; Amin, B.; Nguyen, C., V |
|
| |
Title |
Interfacial characteristics, Schottky contact, and optical performance of a graphene/Ga2SSe van der Waals heterostructure: Strain engineering and electric field tunability |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
102 |
Issue |
7 |
Pages |
075414-10 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Two-dimensional graphene-based van der Waals heterostructures have received considerable interest because of their intriguing characteristics compared with the constituent single-layer two-dimensional materials. Here, we investigate the interfacial characteristics, Schottky contact, and optical performance of graphene/Ga2SSe van der Waals (vdW) heterostructure using first-principles calculations. The effects of stacking patterns, electric gating, and interlayer coupling on the interfacial properties of graphene/Ga2SSe heterostructures are also examined. Our results demonstrate that the Dirac cone of graphene is well preserved at the F point in all stacking patterns due to the weak vdW interactions, which keep the heterostructures feasible such that they can be obtained in further experiments. Moreover, depending on the stacking patterns, a small band gap of about 13-17 meV opens in graphene and has a high carrier mobility, indicating that the graphene/Ga2SSe heterostructures are potential candidates for future high-speed nanoelectronic applications. In the ground state, the graphene/Ga2SSe heterostructures form an n-type Schottky contact. The transformation from an n-type to a p-type Schottky contact or to an Ohmic contact can be forced by electric gating or by varying the interlayer coupling. Our findings could provide physical guidance for designing controllable Schottky nanodevices with high electronic and optical performances. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000557294500006 |
Publication Date |
2020-08-07 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
12 |
Open Access |
|
|
| |
Notes |
; This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant No. 103.01-2019.05. The authors declare that there are no conflicts of interest regarding the publication of this paper. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
|
| |
Call Number |
UA @ admin @ c:irua:171163 |
Serial |
6549 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bafekry, A.; Neek-Amal, M. |
|
| |
Title |
Tuning the electronic properties of graphene-graphitic carbon nitride heterostructures and heterojunctions by using an electric field |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
101 |
Issue |
8 |
Pages |
085417-10 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Integration of graphene-based two-dimensional materials is essential for nanoelectronics applications. Using density-functional theory, we systematically investigate the electronic properties of vertically stacked graphene-graphitic carbon nitrides (GE/GCN). We also studied the covalently lateral stitched graphene-graphitic carbon nitrides (GE-GCN heterojunctions). The effects of perpendicular electric field on the electronic properties of six different heterostructures, i.e., (i) one layer of GE on top of a layer of CnNm with (n, m) = (3,1), (3,4), and (4,3) and (ii) three heterostructures CnNm/Cn'Nm', where (n, m) not equal (n', m') are elucidated. The most important calculated features are (i) the systems GE/C3N4, C3N/C3N4, GE-C3N, GE-C4N3, and C3N-C3N4 exhibit semiconducting characteristics having small band gaps of Delta(0)=20, 250, 100, 100, 80 meV, respectively while (ii) the systems GE/C4N3, C3N/C4N3, and C3N-C4N3 show ferromagnetic-metallic properties. In particular, we found that, in semiconducting heterostructures, the band gap increases nontrivially with increasing the absolute value of the applied perpendicular electric field. This work is useful for designing heterojunctions and heterostructures made of graphene and other two-dimensional materials such as those proposed in recent experiments [X. Liu and M. C. Hersam Sci. Adv. 5, 6444 (2019)]. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000515659700007 |
Publication Date |
2020-02-26 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
24 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
|
| |
Call Number |
UA @ admin @ c:irua:167760 |
Serial |
6640 |
|
| Permanent link to this record |
