Records |
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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000640649500012 |
Publication Date |
2021-03-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2470-1343 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:178395 |
Serial |
7017 |
Permanent link to this record |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000502548500044 |
Publication Date |
2019-10-22 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0008-6223 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.9 |
Times cited |
49 |
Open Access |
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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 |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000523409400037 |
Publication Date |
2020-02-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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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 |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000503453100001 |
Publication Date |
2019-11-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1439-4235 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.9 |
Times cited |
27 |
Open Access |
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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 |
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Author |
Bafekry, A.; Stampfl, C.; Naseri, M.; Fadlallah, M.M.; Faraji, M.; Ghergherehchi, M.; Gogova, D.; Feghhi, S.A.H. |
Title |
Effect of electric field and vertical strain on the electro-optical properties of the MoSi2N4 bilayer : a first-principles calculation |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
Volume |
129 |
Issue |
15 |
Pages |
155103 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Recently, a two-dimensional (2D) MoSi 2N 4 (MSN) structure has been successfully synthesized [Hong et al., Science 369(6504), 670-674 (2020)]. Motivated by this result, we investigate the structural, electronic, and optical properties of MSN monolayer (MSN-1L) and bilayer (MSN-2L) under the applied electric field (E-field) and strain using density functional theory calculations. We find that the MSN-2L is a semiconductor with an indirect bandgap of 1.60 (1.80)eV using Perdew-Burke-Ernzerhof (HSE06). The bandgap of MSN-2L decreases as the E-field increases from 0.1 to 0.6V/angstrom and for larger E-field up to 1.0V/angstrom the bilayer becomes metallic. As the vertical strain increases, the bandgap decreases; more interestingly, a semiconductor to a metal phase transition is observed at a strain of 12 %. Furthermore, the optical response of the MSN-2L is in the ultraviolet (UV) region of the electromagnetic spectrum. The absorption edge exhibits a blue shift by applying an E-field or a vertical compressive strain. The obtained interesting properties suggest MSN-2L as a promising material in electro-mechanical and UV opto-mechanical devices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000640620400003 |
Publication Date |
2021-04-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 2.068 |
Call Number |
UA @ admin @ c:irua:178233 |
Serial |
6981 |
Permanent link to this record |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000562795700001 |
Publication Date |
2020-01-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.6 |
Times cited |
29 |
Open Access |
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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 |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000549894000018 |
Publication Date |
2020-06-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.3 |
Times cited |
18 |
Open Access |
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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 |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000670553900001 |
Publication Date |
2021-06-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 4.123 |
Call Number |
UA @ admin @ c:irua:179827 |
Serial |
7042 |
Permanent link to this record |
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Author |
Bafekry, A.; Stampfl, C.; Faraji, M.; Yagmurcukardes, M.; Fadlallah, M.M.; Jappor, H.R.; Ghergherehchi, M.; Feghhi, S.A.H. |
Title |
A Dirac-semimetal two-dimensional BeN4 : thickness-dependent electronic and optical properties |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
118 |
Issue |
20 |
Pages |
203103 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Motivated by the recent experimental realization of a two-dimensional (2D) BeN4 monolayer, in this study we investigate the structural, dynamical, electronic, and optical properties of a monolayer and few-layer BeN4 using first-principles calculations. The calculated phonon band dispersion reveals the dynamical stability of a free-standing BeN4 layer, while the cohesive energy indicates the energetic feasibility of the material. Electronic band dispersions show that monolayer BeN4 is a semi-metal whose conduction and valence bands touch each other at the Sigma point. Our results reveal that increasing the layer number from single to six-layers tunes the electronic nature of BeN4. While monolayer and bilayer structures display a semi-metallic behavior, structures thicker than that of three-layers exhibit a metallic nature. Moreover, the optical parameters calculated for monolayer and bilayer structures reveal that the bilayer can absorb visible light in the ultraviolet and visible regions better than the monolayer structure. Our study investigates the electronic properties of Dirac-semimetal BeN4 that can be an important candidate for applications in nanoelectronic and optoelectronic. Published under an exclusive license by AIP Publishing. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000691329900002 |
Publication Date |
2021-05-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951; 1077-3118 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
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Open Access |
Not_Open_Access |
Notes |
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Approved |
Most recent IF: 3.411 |
Call Number |
UA @ admin @ c:irua:181725 |
Serial |
6980 |
Permanent link to this record |
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Author |
Bafekry, A.; Stampfl, C.; Ghergherehchi, M. |
Title |
Strain, electric-field and functionalization induced widely tunable electronic properties in MoS2/BC3, /C3N and / C3N4 van der Waals heterostructures |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nanotechnology (Bristol. Print) |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
295202 pp |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
In this paper, the effect of BC3, C3N and C3N4BC(3) and MoS2/C(3)N4 heterostructures are direct semiconductors with band gaps of 0.4 and 1.74 eV, respectively, while MoS2/C3N is a metal. Furthermore, the influence of strain and electric field on the electronic structure of these van der Waals heterostructures is investigated. The MoS2/BC3 heterostructure, for strains larger than -4%, transforms it into a metal where the metallic character is maintained for strains larger than -6%. The band gap decreases with increasing strain to 0.35 eV (at +2%), while for strain (>+6%) a direct-indirect band gap transition is predicted to occur. For the MoS2/C3N heterostructure, the metallic character persists for all strains considered. On applying an electric field, the electronic properties of MoS2/C3N4 are modified and its band gap decreases as the electric field increases. Interestingly, the band gap reaches 30 meV at +0.8 V/angstrom, and with increase above +0.8 V/angstrom, a semiconductor-to-metal transition occurs. Furthermore, we investigated effects of semi- and full-hydrogenation of MoS2/C3N and we found that it leads to a metallic and semiconducting character, respectively. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000532366000001 |
Publication Date |
2020-04-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
0957-4484 |
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
19 |
Open Access |
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Notes |
; This work has supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT)(NRF-2017R1A2B2011989). ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:169523 |
Serial |
6444 |
Permanent link to this record |
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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 ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000510729400042 |
Publication Date |
2019-12-24 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
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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 |
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Author |
Bafekry, A.; Van Nguyen, C.; Stampfl, C.; Akgenc, B.; Ghergherehchi, M. |
Title |
Oxygen vacancies in the single layer of Ti₂CO₂ MXene: effects of gating voltage, mechanical strain, and atomic impurities |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physica Status Solidi B-Basic Solid State Physics |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
|
Issue |
|
Pages |
2000343-2000349 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Herein, using first-principles calculations the structural and electronic properties of the Ti(2)CO(2)MXene monolayer with and without oxygen vacancies are systematically investigated with different defect concentrations and patterns, including partial, linear, local, and hexagonal types. The Ti(2)CO(2)monolayer is found to be a semiconductor with a bandgap of 0.35 eV. The introduction of oxygen vacancies tends to increase the bandgap and leads to electronic phase transitions from nonmagnetic semiconductors to half-metals. Moreover, the semiconducting characteristic of O-vacancy Ti(2)CO(2)can be adjusted via electric fields, strain, and F-atom substitution. In particular, an electric field can be used to alter the nonmagnetic semiconductor of O-vacancy Ti(2)CO(2)into a magnetic one or into a half-metal, whereas the electronic phase transition from a semiconductor to metal can be achieved by applying strain and F-atom substitution. The results provide a useful guide for practical applications of O-vacancy Ti(2)CO(2)monolayers in nanoelectronic and spinstronic nanodevices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000571060800001 |
Publication Date |
2020-09-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.6 |
Times cited |
|
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: 1.6; 2020 IF: 1.674 |
Call Number |
UA @ admin @ c:irua:171948 |
Serial |
6576 |
Permanent link to this record |
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Author |
Bafekry, A.; Stampfl, C.; Peeters, F.M. |
Title |
The electronic, optical, and thermoelectric properties of monolayer PbTe and the tunability of the electronic structure by external fields and defects |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physica Status Solidi B-Basic Solid State Physics |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
|
Issue |
|
Pages |
2000182-12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
First‐principles calculations, within the framework of density functional theory, are used to investigate the structural, electronic, optical, and thermoelectric properties of monolayer PbTe. The effect of layer thickness, electric field, strain, and vacancy defects on the electronic and magnetic properties is systematically studied. The results show that the bandgap decreases as the layer thickness increases from monolayer to bulk. With application of an electric field on bilayer PbTe, the bandgap decreases from 70 meV (0.2 V Å⁻¹) to 50 meV (1 V Å⁻¹) when including spin–orbit coupling (SOC). Application of uniaxial strain induces a direct‐to‐indirect bandgap transition for strain greater than +6%. In addition, the bandgap decreases under compressive biaxial strain (with SOC). The effect of vacancy defects on the electronic properties of PbTe is also investigated. Such vacancy defects turn PbTe into a ferromagnetic metal (single vacancy Pb) with a magnetic moment of 1.3 μB, and into an indirect semiconductor with bandgap of 1.2 eV (single Te vacancy) and 1.5 eV (double Pb + Te vacancy). In addition, with change of the Te vacancy concentration, a bandgap of 0.38 eV (5.55%), 0.43 eV (8.33%), and 0.46 eV (11.11%) is predicted. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000527679200001 |
Publication Date |
2020-04-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-1972 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.6 |
Times cited |
40 |
Open Access |
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Notes |
; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). In addition, this work was supported by the FLAG-ERA project 2DTRANS TMD and the Flemish Science Foundation (FWO-Vl). The authors are thankful for comments by Mohan Verma from the Computational Nanoionics Research Lab, Department of Applied Physics, Bhilai, India and to Francesco Buonocore from ENEA, Casaccia Research Centre, Rome, Italy. ; |
Approved |
Most recent IF: 1.6; 2020 IF: 1.674 |
Call Number |
UA @ admin @ c:irua:168730 |
Serial |
6502 |
Permanent link to this record |
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Author |
Bafekry, A.; Stampfl, C.; Shayesteh, S.F.; Peeters, F.M. |
Title |
Exploiting the novel electronic and magnetic structure of C3Nvia functionalization and conformation |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Advanced Electronic Materials |
Abbreviated Journal |
Adv Electron Mater |
Volume |
5 |
Issue |
5 |
Pages |
1900459 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
2D polyaniline, C3N, is of recent high interest due to its unusual properties and potential use in various technological applications. In this work, through systematic first-principles calculations, the atomic, electronic, and magnetic structure of C3N and the changes induced due to functionalization by the adsorption of hydrogen, oxygen, and fluorine, for different coverages and sites, as well as on formation of nanoribbons including the effect of adsorbed hydrogen and oxygen, and the effect of strain, are investigated. Among other interesting phenomena, for hydrogen adsorption, a semiconductor-to-topological insulator transition, where two Dirac-points appear around the Fermi level, as well as ferromagnetic ordering for both hydrogen and oxygen functionalization, is identified. Considering C3N nanoribbons, adsorption of H leads to significant changes in the electronic properties, such as transforming the structures from semiconductor to metallic. Furthermore, investigating the effect of strain on the physical properties, it is found that the band gap can be significantly altered and controlled. The present findings predict that a wide variation in the magnetic and electronic structure of C3N can be achieved by adatom functionalization and conformation indicating its high potential for use in various technological applications, ranging from catalysis, energy storage, and nanoelectronic devices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000486528200001 |
Publication Date |
2019-09-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2199-160x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.193 |
Times cited |
39 |
Open Access |
|
Notes |
; This work was supported by the FLAG-ERA project 2DTRANS and the Flemish Science Foundation (FWO-Vl). In addition, we acknowledge the OpenMX team for OpenMX code. ; |
Approved |
Most recent IF: 4.193 |
Call Number |
UA @ admin @ c:irua:162790 |
Serial |
5414 |
Permanent link to this record |