NANOlab Center of Excellence literature database -- Query Results

	NANOlab Center of Excellence literature database Home \| Show All \| Simple Search \| Advanced Search	Login Quick Search: Field: contains: ...
	1–30 of 57 records found matching your query (RSS \| history):

Select All Deselect All

<< 1 2 >>

List View

Citations

Details

	Records
	Author	Bafekry, A.; Stampfl, C.; Peeters, F.M.
	Title	The electronic, optical, and thermoelectric properties of monolayer PbTe and the tunability of the electronic structure by external fields and defects			Type	A1 Journal article
	Year	2020	Publication	Physica Status Solidi B-Basic Solid State Physics	Abbreviated Journal	Phys Status Solidi B
	Volume		Issue		Pages	2000182-12
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	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
Permanent link to this record



	Author	Bafekry, A.; Van Nguyen, C.; Stampfl, C.; Akgenc, B.; Ghergherehchi, M.
	Title	Oxygen vacancies in the single layer of Ti₂CO₂ MXene: effects of gating voltage, mechanical strain, and atomic impurities			Type	A1 Journal article
	Year	2020	Publication	Physica Status Solidi B-Basic Solid State Physics	Abbreviated Journal	Phys Status Solidi B
	Volume		Issue		Pages	2000343-2000349
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	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
Permanent link to this record



	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
	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
Permanent link to this record



	Author	Bafekry, A.; Stampfl, C.; Ghergherehchi, M.; Shayesteh, S.F.
	Title	A first-principles study of the effects of atom impurities, defects, strain, electric field and layer thickness on the electronic and magnetic properties of the C2N nanosheet			Type	A1 Journal article
	Year	2020	Publication	Carbon	Abbreviated Journal	Carbon
	Volume	157	Issue	157	Pages	371-384
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using the first-principles calculations, we explore the structural and novel electronic/optical properties of the C2N nanosheet. To this goal, we systematically investigate the affect of layer thickness, electrical field and strain on the electronic properties of the C2N nanosheet. By increasing the thickness of C2N, we observed that the band gap decreases. Moreover, by applying an electrical field to bilayer C2N, the band gap decreases and a semiconductor-to-metal transition can occur. Our results also confirm that uniaxial and biaxial strain can effectively alter the band gap of C2N monolayer. Furthermore, we show that the electronic and magnetic properties of C2N can be modified by the adsorption and substitution of various atoms. Depending on the species of embedded atoms, they may induce semiconductor (O, C, Si and Be), metal (S, N, P, Na, K, Mg and Ca), dilute-magnetic semiconductor (H, F, B), or ferro-magnetic-metal (Cl, Li) character in C2N monolayer. It was also found that the inclusion of hydrogen or oxygen impurities and nitrogen vacancies, can induce magnetism in the C2N monolayer. These extensive calculations can be useful to guide future studies to modify the electronic/optical properties of two-dimensional materials. (C) 2019 Elsevier Ltd. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000502548500044	Publication Date	2019-10-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0008-6223	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	10.9	Times cited	49	Open Access
	Notes	; This work was supported by the National Research Foundation of Korea grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). We are thankful for comments by Meysam Baghery Tagani from department of physics in University of Guilan and Bohayra Mortazavi from Gottfried Wilhelm Leibniz Universitat Hannover, Hannover, Germany. ;			Approved	Most recent IF: 10.9; 2020 IF: 6.337
	Call Number	UA @ admin @ c:irua:165024			Serial	6283
Permanent link to this record



	Author	Bafekry, A.; Yagmurcukardes, M.; Shahrokhi, M.; Ghergherehchi, M.
	Title	Electro-optical properties of monolayer and bilayer boron-doped C₃N: Tunable electronic structure via strain engineering and electric field			Type	A1 Journal article
	Year	2020	Publication	Carbon	Abbreviated Journal	Carbon
	Volume	168	Issue		Pages	220-229
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this work, the structural, electronic and optical properties of monolayer and bilayer of boron doped C3N are investigated by means of density functional theory-based first-principles calculations. Our results show that with increasing the B dopant concentration from 3.1% to 12.5% in the hexagonal pattern, an indirect-to-direct band gap (0.8 eV) transition occurs. Furthermore, we study the effect of electric field and strain on the B doped C3N bilayer (B-C3N@2L). It is shown that by increasing E-field strength from 0.1 to 0.6V/angstrom, the band gap displays almost a linear decreasing trend, while for the > 0.6V/angstrom, we find dual narrow band gap with of 50 meV (in parallel E-field) and 0.4 eV (in antiparallel E-field). Our results reveal that in-plane and out-of-plane strains can modulate the band gap and band edge positions of the B-C3N@2L. Overall, we predict that B-C3N@2L is a new platform for the study of novel physical properties in layered two-dimensional materials (2DM) which may provide new opportunities to realize high-speed low-dissipation devices. (C) 2020 Elsevier Ltd. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000565900900008	Publication Date	2020-07-13
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0008-6223	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	10.9	Times cited	21	Open Access
	Notes	; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government(MSIT) (NRF-2017R1A2B2011989). M. Yagmurcukardes acknowledges Flemish Science Foundation (FWO-VI) by a postdoctoral fellowship. ;			Approved	Most recent IF: 10.9; 2020 IF: 6.337
	Call Number	UA @ admin @ c:irua:171914			Serial	6500
Permanent link to this record



	Author	Bafekry, A.; Obeid, M.; Nguyen, C.; Bagheri Tagani, M.; Ghergherehchi, M.
	Title	Graphene hetero-multilayer on layered platinum mineral Jacutingaite (Pt₂HgSe₃): Van der Waals heterostructures with novel optoelectronic and thermoelectric performances			Type	A1 Journal article
	Year	2020	Publication	Journal Of Materials Chemistry A	Abbreviated Journal	J Mater Chem A
	Volume	8	Issue	26	Pages	13248-13260
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Motivated by the recent successful synthesis of the layered platinum mineral jacutingaite (Pt2HgSe3), we have studied the optoelectronic, mechanical, and thermoelectric properties of graphene hetero-multilayer on Pt(2)HgSe(3)monolayer (PHS) heterostructures (LG/PHS) by using first-principles calculations. PHS is a topological insulator with a band gap of about 160 meV with fully relativistic calculations; when graphene layers are stacked on PHS, a narrow band gap of similar to 10-15 meV opens. In the presence of gate-voltage and out-of plane strain,i.e.pressure, the electronic properties are modified; the Dirac-cone of graphene can be shifted upwards (downward) to a lower (higher) binding energy. The absorption spectrum shows two peaks, which are located around 216 nm (5.74 eV) and protracted to 490 nm (2.53 eV), indicating that PHS could absorb more visible light. Increasing the number of graphene layers on PHS has a positive impact on the UV-vis light absorption and gives a clear red-shift with enhanced absorption intensity. To investigate the electronic performance of the heterostructure, the electrical conductance and thermopower of a device composed of graphene layers and PHS is examined by a combination of DFT and Green function formalism. The number of graphene layers can significantly tune the thermopower and electrical conductance. This analysis reveals that the heterostructures not only significantly affect the electronic properties, but they can also be used as an efficient way to modulate the optic and thermoelectric properties.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000546391600032	Publication Date	2020-05-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2050-7488; 2050-7496	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	11.9	Times cited	20	Open Access
	Notes	; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (NRF-2017R1A2B2011989) and Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 103.01-2019.05. ;			Approved	Most recent IF: 11.9; 2020 IF: 8.867
	Call Number	UA @ admin @ c:irua:169755			Serial	6529
Permanent link to this record



	Author	Bafekry, A.; 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
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000626633500001	Publication Date	2020-12-31
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0039-6028	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.062	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 2.062
	Call Number	UA @ admin @ c:irua:177623			Serial	7026
Permanent link to this record



	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
	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
Permanent link to this record



	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	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
Permanent link to this record



	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
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000640620400003	Publication Date	2021-04-15
	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		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 2.068
	Call Number	UA @ admin @ c:irua:178233			Serial	6981
Permanent link to this record



	Author	Nguyen, D.K.; Hoat, D.M.; Bafekry, A.; Van On, V.; Rivas-Silva, J.F.; Naseri, M.; Cocoletzi, G.H.
	Title	Theoretical prediction of the PtOX (X = S and Se) monolayers as promising optoelectronic and thermoelectric 2D materials			Type	A1 Journal article
	Year	2021	Publication	Physica E-Low-Dimensional Systems & Nanostructures	Abbreviated Journal	Physica E
	Volume	131	Issue		Pages	114732
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	In this paper, two new monolayers, namely PtOS and PtOSe, are theoretically predicted using first-principles calculations. Structural, electronic, optical and thermoelectric properties are explored using full-potential linearized augmented plane-wave (FP-LAPW) method and the semiclassical Boltzmann transport theory. Predicted two-dimensional (2D) materials show good dynamical, thermodynamic and structural stability. Calculated electronic structures indicate the indirect gap semiconductor nature of the PtOS and PtOSe single layers with energy gap of 1.346(2.436) and 0.978(1.978) eV as calculated with the WC(HSE06) functional, respectively. Density of states spectra and valence charge distribution maps suggest a mix of covalent and ionic characters of the chemical bonds. 2D materials at hand exhibit good absorption property in the visible regime with coefficient value reaching the order of 105/cm, even much larger in the ultraviolet, suggesting the promising optoelectronic applicability. Finally, the thermoelectric parameters including electrical conductivity, thermal conductivity, Seebeck coefficient, power factor and figure of merit are determined and analyzed. Results indicate prospective thermoelectric performance of both considered single layers as demonstrated by large figure of merit close to unity. Our work introduces two new 2D multifunctional materials that may possess potential applications in the optoelectronic and thermoelectric nano-devices.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000647410700007	Publication Date	2021-03-25
	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	2.221	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 2.221
	Call Number	UA @ admin @ c:irua:178346			Serial	7030
Permanent link to this record



	Author	Hoat, D.M.; Nguyen, D.K.; Bafekry, A.; Van On, V.; Ul Haq, B.; Rivas-Silva, J.F.; Cocoletzi, G.H.
	Title	Strain-driven modulation of the electronic, optical and thermoelectric properties of beta-antimonene monolayer : a hybrid functional study			Type	A1 Journal article
	Year	2021	Publication	Materials Science In Semiconductor Processing	Abbreviated Journal	Mat Sci Semicon Proc
	Volume	131	Issue		Pages	105878
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Electronic, optical, and thermoelectric properties of the beta-antimonene (beta-Sb) monolayer under the external biaxial strain effects are fully investigated through the first-principles calculations. The studied two-dimensional (2D) system is dynamically and structurally stable as examined via phonon spectrum and cohesive energy. At equilibrium, the beta-Sb single layer exhibits an indirect band gap of 1.310 and 1.786 eV as predicted by the PBE and HSE06 functionals, respectively. Applying external strain may induce the indirect-direct gap transition and significant variation of the energy gap. The calculated optical spectra indicate the enhancement of the optical absorption in a wide energy range from infrared to ultraviolet as induced by the applied strain. In the visible and ultraviolet regime, the absorption coefficient can reach values as large as 82.700 (10(4)/cm) and 91.458 (10(4)/cm). Results suggest that the thermoelectric performance may be improved considerably by applying proper external strain with the figure of merit reaching a value of 0.665. Our work demonstrates that the external biaxial strains may be an effective method to make the beta-Sb monolayer prospective 2D material for optoelectronic and thermoelectric applications.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000663422800002	Publication Date	2021-04-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1369-8001	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.359	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 2.359
	Call Number	UA @ admin @ c:irua:179565			Serial	7021
Permanent link to this record



	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	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
Permanent link to this record



	Author	Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Jappor, H.R.; Hieu, N.N.; Ghergherehchi, M.; Feghhi, S.A.H.; Gogova, D.
	Title	Prediction of two-dimensional bismuth-based chalcogenides Bi₂X₃(X = S, Se, Te) monolayers with orthorhombic structure : a first-principles study			Type	A1 Journal article
	Year	2021	Publication	Journal Of Physics D-Applied Physics	Abbreviated Journal	J Phys D Appl Phys
	Volume	54	Issue	39	Pages	395103
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	First-principles calculation is a very powerful tool for discovery and design of novel two-dimensional materials with unique properties needed for the next generation technology. Motivated by the successful preparation of Bi2S3 nanosheets with orthorhombic structure in the last year, herein we gain a deep theoretical insight into the crystal structure, stability, electronic and optical properties of Bi2X3 (X = S, Se, Te) monolayers of orthorhombic phase employing the first-principles calculations. The Molecular dynamics study, phonon spectra, criteria for elastic stability, and cohesive energy results confirm the desired stability of the Bi2X3 monolayers. From S, to Se and Te, the work function value as well as stability of the systems decrease due to the decline in electronegativity. Mechanical properties study reveals that Bi2X3 monolayers have brittle nature. The electronic bandgap values of Bi2S3, Bi2Se3 and Bi2Te3 monolayers are predicted by the HSE06 functional to be 2.05, 1.20 and 1.16 eV, respectively. By assessing the optical properties, it has been found that Bi2X3 monolayers can absorb ultraviolet light. The high in-plane optical anisotropy offers an additional degree of freedom in the design of optical devices. The properties revealed in our survey will stimulate and inspire the search for new approaches of orthorhombic Bi2X3 (X = S, Se, Te) monolayers synthesis and properties manipulation for fabrication of novel nanoelectronic and optoelectronic devices.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000674464700001	Publication Date	2021-07-06
	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	OpenAccess
	Notes				Approved	Most recent IF: 2.588
	Call Number	UA @ admin @ c:irua:179863			Serial	7014
Permanent link to this record



	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	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.
	Address
	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
Permanent link to this record



	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	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
Permanent link to this record



	Author	Bafekry, A.; Stampfl, C.; Shayesteh, S.F.
	Title	A first-principles study of C₃N nanostructures : control and engineering of the electronic and magnetic properties of nanosheets, tubes and ribbons			Type	A1 Journal article
	Year	2020	Publication	Chemphyschem	Abbreviated Journal	Chemphyschem
	Volume	21	Issue	2	Pages	164-174
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using first-principles calculations we systematically investigate the atomic, electronic and magnetic properties of novel two-dimensional materials (2DM) with a stoichiometry C3N which has recently been synthesized. We investigate how the number of layers affect the electronic properties by considering monolayer, bilayer and trilayer structures, with different stacking of the layers. We find that a transition from semiconducting to metallic character occurs which could offer potential applications in future nanoelectronic devices. We also study the affect of width of C3N nanoribbons, as well as the radius and length of C3N nanotubes, on the atomic, electronic and magnetic properties. Our results show that these properties can be modified depending on these dimensions, and depend markedly on the nature of the edge states. Functionalization of the nanostructures by the adsorption of H adatoms is found induce metallic, half-metallic, semiconducting and ferromagnetic behavior, which offers an approach to tailor the properties, as can the application of strain. Our calculations give insight into this new family of C3N nanostructures, which reveal unusual electronic and magnetic properties, and may have great potential in applications such as sensors, electronics and optoelectronic at the nanoscale.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000503453100001	Publication Date	2019-11-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1439-4235	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.9	Times cited	27	Open Access
	Notes	; ;			Approved	Most recent IF: 2.9; 2020 IF: 3.075
	Call Number	UA @ admin @ c:irua:165045			Serial	6282
Permanent link to this record



	Author	Bafekry, A.; Faraji, M.; Ziabari, A.A.; Fadlallah, M.M.; Nguyen, C., V; Ghergherehchi, M.; Feghhi, S.A.H.
	Title	A van der Waals heterostructure of MoS₂/MoSi₂N₄ : a first-principles study			Type	A1 Journal article
	Year	2021	Publication	New Journal Of Chemistry	Abbreviated Journal	New J Chem
	Volume	45	Issue	18	Pages	8291-8296
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Motivated by the successful preparation of MoSi2N4 monolayers in the last year [Y.-L. Hong et al., Science, 2020, 369, 670-674], we investigate the structural, electronic and optical properties of the MoS2/MoSi2N4 heterostructure (HTS). The phonon dispersion and the binding energy calculations refer to the stability of the HTS. The heterostructure has an indirect bandgap of 1.26 (1.84) eV using PBE (HSE06) which is smaller than the corresponding value of MoSi2N4 and MoS2 monolayers. We find that the work function of the MoS2/MoSi2N4 HTS is smaller than the corresponding value of its individual monolayers. The heterostructure structure can enhance the absorption of light spectra not only in the ultraviolet region but also in the visible region as compared to MoSi2N4 and MoS2 monolayers. The refractive index behaviour of the HTS can be described as the cumulative effect which is well described in terms of a combination of the individual effects (the refractive index of MoSi2N4 and MoS2 monolayers).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000642436200001	Publication Date	2021-03-10
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1144-0546	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.269	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.269
	Call Number	UA @ admin @ c:irua:178300			Serial	6964
Permanent link to this record



	Author	Faraji, M.; Bafekry, A.; Gogova, D.; Hoat, D.M.; Ghergherehchi, M.; Chuong, N.V.; Feghhi, S.A.H.
	Title	Novel two-dimensional ZnO₂, CdO₂ and HgO₂ monolayers: a first-principles-based prediction			Type	A1 Journal article
	Year	2021	Publication	New Journal Of Chemistry	Abbreviated Journal	New J Chem
	Volume	45	Issue		Pages	9368-9374
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this paper, the existence of monolayers with the chemical formula XO2, where X = Zn, Cd, and Hg with hexagonal and tetragonal lattice structures is theoretically predicted by means of first principles calculations. Through cohesive energy calculation and phonon dispersion simulation, it has been proven that the two-dimensional XO2 monolayers proposed are energetically and dynamically stable suggesting their potential experimental realization. Our detailed study demonstrates that these novel newly predicted materials are half-metals and dilute magnetic semiconductors, and they exhibit magnetism in the ground state. The half-metallic character could find many applications in electronic and spintronic devices. Research into the magnetic properties revealed here can enrich theoretical knowledge in this area and provide more potential candidates for XO2 2D-based materials and van der Waals heterostructures.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000645671700001	Publication Date	2021-04-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1144-0546	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.269	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.269
	Call Number	UA @ admin @ c:irua:178245			Serial	7006
Permanent link to this record



	Author	Bafekry, A.; 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	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
Permanent link to this record



	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	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
Permanent link to this record



	Author	Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Khatibani, A.B.; Ziabari, A. abdolahzadeh; Ghergherehchi, M.; Nedaei, S.; Shayesteh, S.F.; Gogova, D.
	Title	Tunable electronic and magnetic properties of MoSi₂N₄ monolayer via vacancy defects, atomic adsorption and atomic doping			Type	A1 Journal article
	Year	2021	Publication	Applied Surface Science	Abbreviated Journal	Appl Surf Sci
	Volume	559	Issue		Pages	149862
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The two dimensional MoSi2N4 (MSN) monolayer exhibiting rich physical and chemical properties was synthesized for the first time last year. We have used the spin-polarized density functional theory to study the effect of different types of point defects on the structural, electronic, and magnetic properties of the MSN monolayer. Adsorbed, substitutionally doped (at different lattice sites), and some kind of vacancies have been considered as point defects. The computational results show all defects studied decrease the MSN monolayer band gap. We found out the H-, O-, and P-doped MSN are n-type conductors. The arsenic-doped MSN, and MSN with vacancy defects have a magnetic moment. The MSN with a Si vacancy defect is a half-metallic which is favorable for spintronic applications, while the MSN with a single N vacancy or double vacancy (N + S) defects are metallic, i. e., beneficial as spin filters and chemical sensors.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000655645300001	Publication Date	2021-05-01
	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	OpenAccess
	Notes				Approved	Most recent IF: 3.387
	Call Number	UA @ admin @ c:irua:179098			Serial	7038
Permanent link to this record



	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	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
Permanent link to this record



	Author	Bafekry, A.; Nguyen, C.; Obeid, M.M.; Ghergherehchi, M.
	Title	Modulating the electro-optical properties of doped C₃N monolayers and graphene bilayersviamechanical strain and pressure			Type	A1 Journal article
	Year	2020	Publication	New Journal Of Chemistry	Abbreviated Journal	New J Chem
	Volume	44	Issue	36	Pages	15785-15792
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this work, we investigated systematically the electronic and optical properties of B doped C3N monolayers as well as B and N doped graphene bilayers (BN-Gr@2L). We found that the doping of B atoms leads to an enlarged band gap of the C3N monolayer and when the dopant concentration reaches 12.5%, an indirect-to-direct band gap switching occurs. In addition, with co-doping of B and N atoms on the graphene monolayer in the hexagonal configuration, an electronic transition from semi-metal to semiconductor occurs. Our optical results for B-C3N show a broad absorption spectrum in a wide visible range starting from 400 nm to 1000 nm with strong absorption intensity, making it a suitable candidate for nanoelectronic and optoelectronic applications. Interestingly, a transition from semi-metal to semiconductor emerges in the graphene monolayer with doping of B and N atoms. Furthermore, our results demonstrate that the in-plane strain and out-of-plane strain (pressure) can modulate the band gap of the BN-Gr@2L. The controllable electronic properties and optical features of the doped graphene bilayer by strain engineering may facilitate their practical performance for various applications in future.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000571972400054	Publication Date	2020-08-18
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1144-0546	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.3	Times cited	7	Open Access
	Notes	; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2017R1A2B2011989). ;			Approved	Most recent IF: 3.3; 2020 IF: 3.269
	Call Number	UA @ admin @ c:irua:171936			Serial	6561
Permanent link to this record



	Author	Bafekry, A.; Stampfl, C.; Akgenc, B.; Ghergherehchi, M.
	Title	Control of C3N4 and C4N3 carbon nitride nanosheets' electronic and magnetic properties through embedded atoms			Type	A1 Journal article
	Year	2020	Publication	Physical Chemistry Chemical Physics	Abbreviated Journal	Phys Chem Chem Phys
	Volume	22	Issue	4	Pages	2249-2261
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In the present work, the effect of various embedded atom impurities on tuning electronic and magnetic properties of C3N4 and C4N3 nanosheets have been studied using first-principles calculations. Our calculations show that C3N4 is a semiconductor and it exhibits extraordinary electronic properties such as dilute-magnetic semiconductor (with H, F, Cl, Be, V, Fe and Co); metal (with N, P, Mg and Ca), half-metal (with Li, Na, K, Al, Sc, Cr, Mn, and Cu) and semiconductor (with O, S, B, C, Si, Ti, Ni and Zn) with the band gaps in the range of 0.3-2.0 eV depending on the species of embedded atom. The calculated electronic properties reveal that C4N3 is a half-metal and it retains half-metallic character with embedded H, O, S, F, B, N, P, Be, Mg, Al, Sc, V, Fe, Ni and Zn atoms. The substitution of Cl, C, Cr and Mn atoms create ferromagnetic-metal character in the C4N3 nanosheet, embedded Co and Cu atoms exhibit a dilute-magnetic semiconductor nature, and embedded Ti atoms result in the system becoming a semiconductor. Therefore, our results reveal the fact that the band gap and magnetism can be modified or induced by various atom impurities, thus, offering effective possibilities to tune the electronic and magnetic properties of C3N4 and C4N3 nanosheets.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000510729400042	Publication Date	2019-12-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1463-9076; 1463-9084	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.3	Times cited	18	Open Access
	Notes	; This work has supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). B. Akgenc acknowledges financial support the Kirklareli University-BAP under the Project No 189 and TUBITAK ULAKBIM, High Performance and Grid Computing Center. ;			Approved	Most recent IF: 3.3; 2020 IF: 4.123
	Call Number	UA @ admin @ c:irua:166553			Serial	6476
Permanent link to this record



	Author	Bafekry, A.; Stampfl, C.; Akgenc, B.; Mortazavi, B.; Ghergherehchi, M.; Nguyen, C.V.
	Title	Embedding of atoms into the nanopore sites of the C₆N₆ and C₆N₈ porous carbon nitride monolayers with tunable electronic properties			Type	A1 Journal article
	Year	2020	Publication	Physical Chemistry Chemical Physics	Abbreviated Journal	Phys Chem Chem Phys
	Volume	22	Issue	11	Pages	6418-6433
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Using first-principles calculations, we study the effect of embedding various atoms into the nanopore sites of both C6N6 and C6N8 monolayers. Our results indicate that the embedded atoms significantly affect the electronic and magnetic properties of C6N6 and C6N8 monolayers and lead to extraordinary and multifarious electronic properties, such as metallic, half-metallic, spin-glass semiconductor and dilute-magnetic semiconductor behaviour. Our results reveal that the H atom concentration dramatically affects the C6N6 monolayer. On increasing the H coverage, the impurity states also increase due to H atoms around the Fermi-level. C6N6 shows metallic character when the H atom concentration reaches 6.25%. Moreover, the effect of charge on the electronic properties of both Cr@C6N6 and C@C6N8 is also studied. Cr@C6N6 is a ferromagnetic metal with a magnetic moment of 2.40 mu(B), and when 0.2 electrons are added and removed, it remains a ferromagnetic metal with a magnetic moment of 2.57 and 2.77 mu(B), respectively. Interestingly, one can observe a semi-metal, in which the VBM and CBM in both spin channels touch each other near the Fermi-level. C@C6N8 is a semiconductor with a nontrivial band gap. When 0.2 electrons are removed, it remains metallic, and under excess electronic charge, it exhibits half-metallic behaviour.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000523409400037	Publication Date	2020-02-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1463-9076; 1463-9084	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.3	Times cited	17	Open Access
	Notes	; This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2017R1A2B2011989). ;			Approved	Most recent IF: 3.3; 2020 IF: 4.123
	Call Number	UA @ admin @ c:irua:168617			Serial	6504
Permanent link to this record



	Author	Obeid, M.M.; Stampfl, C.; Bafekry, A.; Guan, Z.; Jappor, H.R.; Nguyen, C., V; Naseri, M.; Hoat, D.M.; Hieu, N.N.; Krauklis, A.E.; Tuan V Vu; Gogova, D.
	Title	First-principles investigation of nonmetal doped single-layer BiOBr as a potential photocatalyst with a low recombination rate			Type	A1 Journal article
	Year	2020	Publication	Physical Chemistry Chemical Physics	Abbreviated Journal	Phys Chem Chem Phys
	Volume	22	Issue	27	Pages	15354-15364
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Nonmetal doping is an effective approach to modify the electronic band structure and enhance the photocatalytic performance of bismuth oxyhalides. Using density functional theory, we systematically examine the fundamental properties of single-layer BiOBr doped with boron (B) and phosphorus (P) atoms. The stability of the doped models is investigated based on the formation energies, where the substitutional doping is found to be energetically more stable under O-rich conditions than under Bi-rich ones. The results showed that substitutional doping of P atoms reduced the bandgap of pristine BiOBr to a greater extent than that of boron substitution. The calculation of the effective masses reveals that B doping can render the electrons and holes of pristine BiOBr lighter and heavier, respectively, resulting in a slower recombination rate of photoexcited electron-hole pairs. Based on the results of HOMO-LUMO calculations, the introduction of B atoms tends to increase the number of photocatalytically active sites. The top of the valence band and the conduction band bottom of the B doped BiOBr monolayer match well with the water redox potentials in an acidic environment. The absorption spectra propose that B(P) doping causes a red-shift. Overall, the results predict that nonmetal-doped BiOBr monolayers have a reduced bandgap, a slow recombination rate, more catalytically active sites, enhanced optical absorption edges, and reduced work functions, which will contribute to superior photocatalytic performance.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000549894000018	Publication Date	2020-06-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1463-9076; 1463-9084	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.3	Times cited	18	Open Access
	Notes	; This work was partially supported by the financial support from the Natural Science Foundation of China (Grant No. 11904203) and the Fundamental Research Funds of Shandong University (Grant No. 2019GN065). ;			Approved	Most recent IF: 3.3; 2020 IF: 4.123
	Call Number	UA @ admin @ c:irua:171235			Serial	6522
Permanent link to this record



	Author	Bafekry, A.; Stampfl, C.; Faraji, M.; Yagmurcukardes, M.; Fadlallah, M.M.; Jappor, H.R.; Ghergherehchi, M.; Feghhi, S.A.H.
	Title	A Dirac-semimetal two-dimensional BeN4 : thickness-dependent electronic and optical properties			Type	A1 Journal article
	Year	2021	Publication	Applied Physics Letters	Abbreviated Journal	Appl Phys Lett
	Volume	118	Issue	20	Pages	203103
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Motivated by the recent experimental realization of a two-dimensional (2D) BeN4 monolayer, in this study we investigate the structural, dynamical, electronic, and optical properties of a monolayer and few-layer BeN4 using first-principles calculations. The calculated phonon band dispersion reveals the dynamical stability of a free-standing BeN4 layer, while the cohesive energy indicates the energetic feasibility of the material. Electronic band dispersions show that monolayer BeN4 is a semi-metal whose conduction and valence bands touch each other at the Sigma point. Our results reveal that increasing the layer number from single to six-layers tunes the electronic nature of BeN4. While monolayer and bilayer structures display a semi-metallic behavior, structures thicker than that of three-layers exhibit a metallic nature. Moreover, the optical parameters calculated for monolayer and bilayer structures reveal that the bilayer can absorb visible light in the ultraviolet and visible regions better than the monolayer structure. Our study investigates the electronic properties of Dirac-semimetal BeN4 that can be an important candidate for applications in nanoelectronic and optoelectronic. Published under an exclusive license by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000691329900002	Publication Date	2021-05-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951; 1077-3118	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 3.411
	Call Number	UA @ admin @ c:irua:181725			Serial	6980
Permanent link to this record



	Author	Bafekry, A.; Sarsari, I.A.; Faraji, M.; Fadlallah, M.M.; Jappor, H.R.; Karbasizadeh, S.; Nguyen, V.; Ghergherehchi, M.
	Title	Electronic and magnetic properties of two-dimensional of FeX (X = S, Se, Te) monolayers crystallize in the orthorhombic structures			Type	A1 Journal article
	Year	2021	Publication	Applied Physics Letters	Abbreviated Journal	Appl Phys Lett
	Volume	118	Issue	14	Pages	143102
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this Letter, we explore the lattice, dynamical stability, and electronic and magnetic properties of FeTe bulk and FeX (X=S, Se, Te) monolayers using the density functional calculations. The phonon dispersion relation, elastic stability criteria, and cohesive energy results show the stability of studied FeX monolayers. The mechanical properties reveal that all FeX monolayers have a brittle nature. Furthermore, these structures are stable as we move down the 6A group in the periodic table, i.e., from S, Se, and Te. The stability and work function decrease as the electronegativity decreases. The spin-polarized electronic structures demonstrate that the FeTe monolayer has a total magnetization of 3.8 mu (B), which is smaller than the magnetization of FeTe bulk (4.7 mu (B)). However, FeSe and FeS are nonmagnetic monolayers. The FeTe monolayer can be a good candidate material for spin filter applications due to its electronic and magnetic properties. This study highlights the bright prospect for the application of FeX monolayers in electronic structures.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000637703700001	Publication Date	2021-04-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951; 1077-3118	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.411
	Call Number	UA @ admin @ c:irua:177731			Serial	6985
Permanent link to this record



	Author	Bafekry, A.; Shahrokhi, M.; Shafique, A.; Jappor, H.R.; Shojaei, F.; Feghhi, S.A.H.; Ghergherehchi, M.; Gogova, D.
	Title	Two-dimensional carbon nitride C₆N nanosheet with egg-comb-like structure and electronic properties of a semimetal			Type	A1 Journal article
	Year	2021	Publication	Nanotechnology	Abbreviated Journal	Nanotechnology
	Volume	32	Issue	21	Pages	215702
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	In this study, the structural, electronic and optical properties of theoretically predicted C6N monolayer structure are investigated by means of Density Functional Theory-based First-Principles Calculations. Phonon band dispersion calculations and molecular dynamics simulations reveal the dynamical and thermal stability of the C6N single-layer structure. We found out that the C6N monolayer has large negative in-plane Poisson's ratios along both X and Y direction and the both values are almost four times that of the famous-pentagraphene. The electronic structure shows that C6N monolayer is a semi-metal and has a Dirac-point in the BZ. The optical analysis using the random phase approximation method constructed over HSE06 illustrates that the first peak of absorption coefficient of the C6N monolayer along all polarizations is located in the IR range of spectrum, while the second absorption peak occurs in the visible range, which suggests its potential applications in optical and electronic devices. Interestingly, optically anisotropic character of this system is highly desirable for the design of polarization-sensitive photodetectors. Thermoelectric properties such as Seebeck coefficient, electrical conductivity, electronic thermal conductivity and power factor are investigated as a function of carrier doping at temperatures 300, 400, and 500 K. In general, we predict that the C6N monolayer could be a new platform for study of novel physical properties in two-dimensional semi-metal materials, which may provide new opportunities to realize high-speed low-dissipation devices.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000624531500001	Publication Date	2020-12-18
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0957-4484	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.44	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.44
	Call Number	UA @ admin @ c:irua:176648			Serial	6740
Permanent link to this record