| Records |
| Author |
Bafekry, A.; Shayesteh, S.F.; Ghergherehchi, M.; Peeters, F.M. |
| Title |
Tuning the bandgap and introducing magnetism into monolayer BC3 by strain/defect engineering and adatom/molecule adsorption |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
126 |
Issue |
14 |
Pages |
144304 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using first-principles calculations, we study the structural, electronic, and optical properties of pristine BC3. Our results show that BC3 is a semiconductor which can be useful in optoelectronic device applications. Furthermore, we found that the electronic properties of BC3 can be modified by strain and the type of edge states. With increasing thickness, the indirect bandgap decreases from 0.7 eV (monolayer) to 0.27 eV (bulk). Upon uniaxial tensile strain along the armchair and zigzag directions, the bandgap slightly decreases, and with increasing uniaxial strain, the bandgap decreases, and when reaching -8%, a semiconductor-to-metal transition occurs. By contrast, under biaxial strain, the bandgap increases to 1.2 eV in +8% and decreases to zero in -8%. BC3 nanoribbons with different widths exhibit magnetism at the zigzag edges, while, at the armchair edges, they become semiconductor, and the bandgap is in the range of 1.0-1.2 eV. Moreover, we systematically investigated the effects of adatoms/molecule adsorption and defects on the structural, electronic, and magnetic properties of BC3. The adsorption of various adatoms and molecules as well as topological defects (vacancies and Stone-Wales defects) can modify the electronic properties. Using these methods, one can tune BC3 into a metal, half-metal, ferromagnetic-metal, and dilute-magnetic semiconductor or preserve its semiconducting character. Published under license by AIP Publishing. |
| 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 |
000503995300019 |
Publication Date |
2019-10-10 |
| 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 |
56 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 2.068 |
| Call Number |
UA @ admin @ c:irua:165160 |
Serial |
6328 |
| 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 |
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 |
|
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.; Shahrokhi, M.; Yagmurcukardes, M.; Gogova, D.; Ghergherehchi, M.; Akgenc, B.; Feghhi, S.A.H. |
| Title |
Surface functionalization of the honeycomb structure of zinc antimonide (ZnSb) monolayer : a first-principles study |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Surface Science |
Abbreviated Journal |
Surf Sci |
| Volume |
707 |
Issue |
|
Pages |
121796 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Structural, electronic, optic and vibrational properties of Zinc antimonide (ZnSb) monolayers and their func-tionalized (semi-fluorinated and fully chlorinated) structures are investigated by means of the first-principles calculations. The phonon dispersion curves reveal the presence of imaginary frequencies and thus confirm the dynamical instability of ZnSb monolayer. The calculated electronic band structure corroborates the metallic character with fully-relativistic calculations. Moreover, we analyze the surface functionalization effect on the structural, vibrational, and electronic properties of the pristine ZnSb monolayer. The semi-fluorinated and fully-chlorinated ZnSb monolayers are shown to be dynamically stable in contrast to the ZnSb monolayer. At the same time, semi-fluorination and fully-chlorination of ZnSb monolayer could effectively modulate the metallic elec-tronic properties of pristine ZnSb. In addition, a magnetic metal to a nonmagnetic semiconductor transition with a band gap of 1 eV is achieved via fluorination, whereas a transition to a semiconducting state with 1.4 eV band gap is found via chlorination of the ZnSb monolayer. According to the optical properties analysis, the first ab-sorption peaks of the fluorinated-and chlorinated-ZnSb monolayers along the in-plane polarization are placed in the infrared range of spectrum, while they are in the middle ultraviolet for the out-of-plane polarization. Interestingly, the optically anisotropic behavior of these novel monolayers along the in-plane polarizations is highly desirable for design of polarization-sensitive photodetectors. The results of the calculations clearly proved that the tunable electronic properties of the ZnSb monolayer can be realized by chemical functionalization for application in the next generation 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 |
000626633500001 |
Publication Date |
2020-12-31 |
| 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 |
0039-6028 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.062 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
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Approved |
Most recent IF: 2.062 |
| Call Number |
UA @ admin @ c:irua:177623 |
Serial |
7026 |
| Permanent link to this record |
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| Author |
Bafekry, A.; Ghergherehchi, M.; Shayesteh, S.F.; Peeters, F.M. |
| Title |
Adsorption of molecules on C3N nanosheet : a first-principles calculations |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Chemical physics |
Abbreviated Journal |
Chem Phys |
| Volume |
526 |
Issue |
526 |
Pages |
110442 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using first-principles calculations we investigate the interaction of various molecules, including H-2, N-2, CO, CO2, H2O, H2S, NH3, CH4 with a C3N nanosheet. Due to the weaker interaction between H-2, N-2, CO, CO2, H2O, H2S, NH3, and CH4 molecules with C3N, the adsorption energy is small and does not yield any significant distortion of the C3N lattice and the molecules are physisorbed. Calculated charge transfer shows that these molecules act as weak donors. However, adsorption of O-2, NO, NO2 and SO2 molecules are chemisorbed, they receive electrons from C3N and act as a strong acceptor. They interact strongly through hybridizing its frontier orbitals with the p-orbital of C3N, modifying the electronic structure of C3N. Our theoretical studies indicate that C3N-based sensor has a high potential for O-2, NO, NO2 and SO2 molecules detection. |
| 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 |
000481606000006 |
Publication Date |
2019-07-09 |
| 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 |
0301-0104 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.767 |
Times cited |
52 |
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 and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 1.767 |
| Call Number |
UA @ admin @ c:irua:161779 |
Serial |
5405 |
| 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 |
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Issue |
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Pages |
2000343-2000349 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
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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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 |
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Series Issue |
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Edition |
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| ISSN |
0370-1972 |
ISBN |
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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.; 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 |
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. |
| 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 |
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.; 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 |
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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 |
