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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 (up) 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
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000481606000006 Publication Date 2019-07-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0301-0104 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.767 Times cited 46 Open Access
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
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Author Bafekry, A.; Mortazavic, B.; Shayesteh, S.F.
Title Band gap and magnetism engineering in Dirac half-metallic Na2C nanosheet via layer thickness, strain and point defects Type A1 Journal article
Year 2019 Publication Journal of magnetism and magnetic materials Abbreviated Journal J Magn Magn Mater
Volume 491 Issue 491 Pages 165565
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Na2C is a novel two-dimensional material with Dirac Half-metal (DHM) characteristic, exhibiting a combination of single-spin massless Dirac fermions and half-semimetal. In this paper based on the first-principles calculations, we studied the mechanical, electronic, magnetic and optical properties of Na2C nanosheet. The elastic modulus of Na2C was measured to 18.5 N/m and isotropic, whereas it shows anisotropic tensile strengths of 2.85 and 2.04 N/m, for the loading along the zigzag and armchair directions, respectively. We found that Na2C, is a DHM with band gap of 0.7 eV in the up-spin channel and has 2 mu(B) magnetic moment per unit cell. In addition, we investigated the effects of number of atomic layers (thickness), electric field and strain on the possibility of further tuning of the electronic and magnetic properties of Na2C. Our calculations show that by increasing the number of layers from monolayer to bulk, a transition from DHM to ferromagnetic metal occurs with a high magnetic moments in the range of 16-30 mu(B). With applying an electric field on the Na2C bilayer (within the ferromagnetic and anti-ferromagnetic orders), energy band gap is slightly increased. In addition our results indicate that the electronic structure can be significantly modified by applying the mechanical straining. In this regard, under the biaxial strain (from 0% to – 8%) or large uniaxial strains (> – 6%), we observed the DHM to ferromagnetic-metal transition. Moreover, vacancy defects and atom substitutions can also effect the electronic and magnetic properties of Na2C nanosheet. Defective Na2C with single and double vacancies, was found to show the metallic response. With various atom substitutions this nanosheet exhibits; ferromagnetic-metal (Si and Be) with 5.2 and 3 mu(B); dilute-magnetic semiconductor (B and N) with 3 and 7 mu(B) magnetic moments, respectively. In the case of B or N atoms replacing the native C atom, the down-spin channel yields about 1 eV band gap. Interestingly, replacing the Na atoms in the native Na2C lattice with the Li can result in the formation of magnetic topological insulator phase with nontrivial band gap in the down-spin channel (25 meV and 0.15 eV) and up-spin channel (0.75 eV), in addition exhibit 8 mu(B) magnetic moment in the ground state.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000486396100010 Publication Date 2019-07-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.63 Times cited 13 Open Access
Notes ; B. M. appreciates the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germanys Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453). We acknowledge OpenMX team for OpenMX code. ; Approved Most recent IF: 2.63
Call Number UA @ admin @ c:irua:163697 Serial 5408
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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 (up) 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
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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 (up) 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.
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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
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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 (up) 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
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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 (up) 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.
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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
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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 (up) 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
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000503995300019 Publication Date 2019-10-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 48 Open Access
Notes Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:165160 Serial 6328
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Author Bafekry, A.; Shayesteh, S.F.; Peeters, F.M.
Title Two-dimensional carbon nitride (2DCN) nanosheets : tuning of novel electronic and magnetic properties by hydrogenation, atom substitution and defect engineering Type A1 Journal article
Year 2019 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 126 Issue 21 Pages 215104
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract By employing first-principles calculations within the framework of density functional theory, we investigated the structural, electronic, and magnetic properties of graphene and various two-dimensional carbon-nitride (2DNC) nanosheets. The different 2DCN gives rise to diverse electronic properties such as metals (C3N2), semimetals (C4N and C9N4), half-metals (C4N3), ferromagnetic-metals (C9N7), semiconductors (C2N, C3N, C3N4, C6N6, and C6N8), spin-glass semiconductors (C10N9 and C14N12), and insulators (C2N2). Furthermore, the effects of adsorption and substitution of hydrogen atoms as well as N-vacancy defects on the electronic and magnetic properties are systematically studied. The introduction of point defects, including N vacancies, interstitial H impurity into graphene and different 2DCN crystals, results in very different band structures. Defect engineering leads to the discovery of potentially exotic properties that make 2DCN interesting for future investigations and emerging technological applications with precisely tailored properties. These properties can be useful for applications in various fields such as catalysis, energy storage, nanoelectronic devices, spintronics, optoelectronics, and nanosensors. Published under license by AIP Publishing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000504007300023 Publication Date 2019-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 57 Open Access
Notes Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:165733 Serial 6329
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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 (up) 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
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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 (up) 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
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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 (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract 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
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000527679200001 Publication Date 2020-04-23
Series Editor Series Title Abbreviated Series Title
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 37 Open Access
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
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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 (up) 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
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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 (up) 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
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Author Bafekry, A.
Title Graphene-like BC₆N single-layer: tunable electronic and magnetic properties via thickness, gating, topological defects, and adatom/molecule Type A1 Journal article
Year 2020 Publication Physica E-Low-Dimensional Systems & Nanostructures Abbreviated Journal Physica E
Volume 118 Issue Pages 113850-15
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract By using density functional theory-based first-principles calculations, we investigate the structural, electronic, optical, and transport properties of pristine single-layer BC6N. Under different external actions and functionalization. Increasing the thickness of the structure results in a decrease of the band gap. Applying a perpendicular electric field decreases the band gap and a semiconductor-to-topological insulator transition is revealed. Uniaxial and biaxial strains of +8% result in a semiconductor-to-metal transition. Nanoribbons of BC6N having zigzag edge with even (odd) values of widths, become metal (semiconductor), while the armchair edge nanoribbons exhibit robust semiconducting behavior. In addition, we systematically investigate the effect of surface adatom and molecule, substitutional impurity and defect engineering on the electronic properties of single-layer BC6N and found transitions from metal to half-metal, to ferromagnetic metal, to dilute magnetic semiconductor, and even to spin-glass semiconductor. Furthermore we found that, topological defects including vacancies and Stone–Wales type, induce magnetism in single-layer BC6N.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000515321700032 Publication Date 2019-12-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited 30 Open Access
Notes ; ; Approved Most recent IF: 3.3; 2020 IF: 2.221
Call Number UA @ admin @ c:irua:169750 Serial 6530
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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 (up) 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
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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 (up) 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
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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 (up) 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
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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 (up) 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
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000571060800001 Publication Date 2020-09-04
Series Editor Series Title Abbreviated Series Title
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
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Author Bafekry, A.; Akgenc, B.; Ghergherehchi, M.; Peeters, F.M.
Title Strain and electric field tuning of semi-metallic character WCrCO₂ MXenes with dual narrow band gap Type A1 Journal article
Year 2020 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 32 Issue 35 Pages 355504-355508
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Motivated by the recent successful synthesis of double-M carbides, we investigate structural and electronic properties of WCrC and WCrCO2 monolayers and the effects of biaxial and out-of-plane strain and electric field using density functional theory. WCrC and WCrCO2 monolayers are found to be dynamically stable. WCrC is metallic and WCrCO2 display semi-metallic character with narrow band gap, which can be controlled by strain engineering and electric field. WCrCO2 monolayer exhibits a dual band gap which is preserved in the presence of an electric field. The band gap of WCrCO2 monolayer increases under uniaxial strain while it becomes metallic under tensile strain, resulting in an exotic 2D double semi-metallic behavior. Our results demonstrate that WCrCO2 is a new platform for the study of novel physical properties in two-dimensional Dirac materials and which may provide new opportunities to realize high-speed low-dissipation devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000539375800001 Publication Date 2020-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.7 Times cited 37 Open Access
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 Flemish Science Foundation (FW0-Vl). ; Approved Most recent IF: 2.7; 2020 IF: 2.649
Call Number UA @ admin @ c:irua:169756 Serial 6616
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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 (up) 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
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Author Bafekry, A.; Akgenc, B.; Shayesteh, S.F.; Mortazavi, B.
Title Tunable electronic and magnetic properties of graphene/carbon-nitride van der Waals heterostructures Type A1 Journal article
Year 2020 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 505 Issue Pages 144450-144459
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this paper, we explore the electronic properties of C3N, C3N4 and C4N3 and graphene (Gr) van der Waals heterostructures by conducing extensive first-principles calculations. The acquired results show that these heterostructures can show diverse electronic properties, such as the metal (Gr on C3N), semiconductor with narrow band gap (Gr on C3N4) and ferromagnetic-metal (Gr on C4N3). We furthermore explored the effect of vacancies, atom substitution, topological, antisite and Stone-Wales defects on the structural and electronic properties of considered heterostructures. Our results show that the vacancy defects introduce localized states near the Fermi level and create a local magnetic moment. The Gr/C3N heterostructures with the single and double vacancy defects exhibit a ferromagnetic-metal, while Stone-Wales defects show an indirect semiconductor with the band gap of 0.2 eV. The effects of adsorption and insertion of O, C, Be, Cr, Fe and Co atoms on the electronic properties of Gr/C3N have been also elaborately studied. Our results highlight that the electronic and magnetic properties of garphene/carbon-nitride lateral heterostructures can be effectively modified by point defects and impurities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000510846500052 Publication Date 2019-11-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 26 Open Access
Notes ; ; Approved Most recent IF: 6.7; 2020 IF: 3.387
Call Number UA @ admin @ c:irua:167732 Serial 6638
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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 (up) 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
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Author Bafekry, A.; Neek-Amal, M.; Peeters, F.M.
Title Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering Type A1 Journal article
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 16 Pages 165407-165408
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using first-principle calculations, we systematically study strain tuning of the electronic properties of two- dimensional graphitic carbon nitride nanosheets with empirical formula CnNm. We found the following: (i) the ferromagnetic ordered state in the metal-free systems (n, m) = (4,3), (10,9), and (14,12) remains stable in the presence of strain of about 6%. However, the system (9,7) loses its ferromagnetic ordering when increasing strain. This is due to the presence of topological defects in the (9,7) system, which eliminates the asymmetry between spin up and spin down of the p(z) orbitals when strain is applied. (ii) By applying uniaxial strain, a band gap opens in systems which are initially gapless. (iii) In semiconducting systems which have an initial gap of about 1 eV, the band gap is closed with applying uniaxial strain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000523630200012 Publication Date 2020-04-06
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 22 Open Access
Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:168560 Serial 6643
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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 (up) 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 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 (up) 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
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Author Obeid, M.M.; Bafekry, A.; Rehman, S.U.; Nguyen, C., V.
Title A type-II GaSe/HfS₂ van der Waals heterostructure as promising photocatalyst with high carrier mobility Type A1 Journal article
Year 2020 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 534 Issue Pages 147607
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this paper, the electronic, optical, and photocatalytic properties of GaSe/HfS2 heterostructure are studied via first-principles calculations. The stability of the vertically stacked heterobilayers is validated by the binding energy, phonon spectrum, and ab initio molecular dynamics simulation. The results reveal that the most stable GaSe/HfS2 heterobilayer retains a type-II alignment with an indirect bandgap 1.40 eV. As well, the results also show strong optical absorption intensity in the studied heterostructure (1.8 x 10(5) cm(-1)). The calculated hole mobility is 1376 cm(2) V-1 s(-1), while electron mobility reaches 911 cm(2) V-1 s(-1) along the armchair and zigzag directions. By applying an external electric field, the bandgap and band offset of the designed heterostructure can be effectively modified. Remarkably, a stronger external electric field can create nearly free electron states in the vicinity of the bottom of the conduction band, which induces indirect-to-direct bandgap transition as well as a semiconductor-to-metal transition. In contrast, the electronic properties of GaSe/HfS2 heterostructure are predicted to be insensitive to biaxial strain. The current work reveals that GaSe/HfS2 heterostructure is a promising candidate as a novel photocatalytic material for hydrogen generation in the visible range.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000582367700045 Publication Date 2020-08-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 4 Open Access
Notes ; ; Approved Most recent IF: 6.7; 2020 IF: 3.387
Call Number UA @ admin @ c:irua:174301 Serial 6682
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Author Bafekry, A.; Yagmurcukardes, M.; Shahrokhi, M.; Ghergherehchi, M.; Kim, D.; Mortazavi, B.
Title Electro-optical and mechanical properties of Zinc antimonide (ZnSb) monolayer and bilayer : a first-principles study Type A1 Journal article
Year 2021 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 540 Issue 1 Pages 148289
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Latest synthesis of ZnSb monolayer, encouraged us to conduct density functional theory (DFT) simulations in order to study the structural, magnetic, electronic/optical and mechanical features of the sp2-hybridized honeycomb ZnSb monolayer (ML-ZnSb) and bilayer (BL-ZnSb). Our structural optimizations reveal that ML-ZnSb is an anisotropic hexagonal structure while BL-ZnSb is composed of shifted ZnSb layers which are covalently binded. ML-ZnSb is found to be a ferromagnetic metal, in contrast BL-ZnSb has a non-magnetic indirect band gap semiconducting ground state. For the in-plane polarization, first absorption peak of ML-ZnSb and BL-ZnSb confirm the absorbance of the light within the infrared domain wand visible range, respectively. Moreover, our results reveal that the layer-layer chemical bonding in BL-ZnSb significantly enhances the mechanical response of ML-ZnSb whose in-plane stiness is the smallest among all 2D materials (2DM). Notably, the strong in-plane anisotropy of ML-ZnSb in its stiness reduces in BL-ZnSb.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000599883200005 Publication Date 2020-11-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited 1 Open Access Not_Open_Access
Notes ; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). Computational resources were provided by the Flemish Supercomputer Center (VSC). M.Y. is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship. B.M. and X. Z. appreciate the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germanys Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453). ; Approved Most recent IF: 3.387
Call Number UA @ admin @ c:irua:174956 Serial 6688
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Author Bafekry, A.; Faraji, M.; Hoat, D.M.; Shahrokhi, M.; Fadlallah, M.M.; Shojaei, F.; Feghhi, S.A.H.; Ghergherehchi, M.; Gogova, D.
Title MoSi₂N₄ single-layer : a novel two-dimensional material with outstanding mechanical, thermal, electronic and optical properties Type A1 Journal article
Year 2021 Publication Journal Of Physics D-Applied Physics Abbreviated Journal J Phys D Appl Phys
Volume 54 Issue 15 Pages 155303
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Very recently, the 2D form of MoSi2N4 has been successfully fabricated (Hong et al 2020 Science 369 670). Motivated by these recent experimental results, we investigate the structural, mechanical, thermal, electronic and optical properties of the MoSi2N4 monolayer. The mechanical study confirms the stability of the MoSi2N4 monolayer. The Young's modulus decreases by similar to 30%, while the Poisson's ratio increases by similar to 30% compared to the corresponding values of graphene. In addition, the MoSi2N4 monolayer's work function is very similar to that of phosphorene and MoS2 monolayers. The electronic structure shows that the MoSi2N4 monolayer is an indirect semiconductor with a band gaps of 1.79 (2.35) eV using the GGA (HSE06) functional. The thermoelectric performance of the MoSi2N4 monolayer has been revealed and a figure of merit slightly larger than unity at high temperatures is calculated. The optical analysis shows that the first absorption peak for in-plane polarization is located in the visible range of the spectrum, therefore, the MoSi2N4 monolayer is a promising candidate for advanced optoelectronic nanodevices. In summary, the fascinating MoSi2N4 monoloayer is a promising 2D material for many applications due to its unique physical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000613849300001 Publication Date 2021-01-14
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 2.588 Times cited Open Access Not_Open_Access
Notes ; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2015M2B2A4033123). Computational resources were provided by the Flemish Supercomputer Center (VSC) and TUBITAK ULAKBIM, High Performance and Grid Computing Center (Tr-Grid e-Infrastructure). ; Approved Most recent IF: 2.588
Call Number UA @ admin @ c:irua:176167 Serial 6693
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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 (up) 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
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Author Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Ziabari, A.A.; Khatibani, A.B.; Feghhi, S.A.H.; Ghergherehchi, M.; Gogova, D.
Title Adsorption of habitat and industry-relevant molecules on the MoSi₂N₄ monolayer Type A1 Journal article
Year 2021 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 564 Issue Pages 150326
Keywords (up) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The adsorption of various environmental gas molecules, including H-2, N-2, CO, CO2, O-2, NO, NO2, SO2 H2O, H2S, NH3 and CH4, on the surface of the recently synthesized two dimensional MoSi2N4 (MSN) monolayer has been investigated by means of spin-polarized first-principles calculations. The most stable adsorption configuration, adsorption energy, and charge transfer have been computed. Due to the weak interaction between molecules studied with the MSN monolayer surface, the adsorption energy is small and does not yield any significant distortion of the MSN lattice, i.e., the interaction between the molecules and MSN monolayer surface is physisorption. We find that all molecules are physisorbed on the MSM surface with small charge transfer, acting as either charge acceptors or donors. The MSN monolayer is a semiconductor with an indirect band gap of 1.79 eV. Our theoretical estimations reveal that upon adsorption of H-2, N-2, CO, CO2, NO, H2O, H2S, NH3 and CH4 molecules, the semiconducting character of MSN monolayer is preserved and the band gap value is decreased to similar to 1.5 eV. However, the electronic properties of the MSN monolayer can be significantly altered by adsorption of O-2, NO and SO2, and a spin polarization with magnetic moments of 2, 1, 2 mu(B), respectively, can be introduced. Furthermore, we demonstrate that the band gap and the magnetic moment of adsorbed MSN monolayer can be significantly modulated by the concentration of NO and SO2 molecules. As the concentration of NO2 molecule increases, the magnetic moment increase from 1 mu(B) to 2 and 3 mu(B). In the case of the SO2 molecule with increasing of concentration, the band gap decreases from 1.2 eV to 1.1 and 0.9 eV. Obviously, our theoretical studies indicate that MSN monolayer-based sensor has a high application potential for O-2, NO, NO2 and SO2 detection.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000675534500002 Publication Date 2021-06-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.387
Call Number UA @ admin @ c:irua:180421 Serial 6970
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