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- Bafekry, A., et al.
(författare)
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A novel two-dimensional boron-carbon-nitride (BCN) monolayer: A first-principles insight
- 2021
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 130:11
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Tidskriftsartikel (refereegranskat)abstract
- The optical, electronic, and structural properties of a theoretically predicted new boron-carbon-nitride (BCN) two-dimensional monolayer have been explored using density functional theory calculations. The phonon dispersion, molecular dynamics simulation, the cohesive energy, and the Born criteria of elastic constant calculations of the BCN monolayer confirm its stability. The phonon spectrum illustrates an out-of-plane flexure mode with quadratic dispersion in the long-wavelength limit. The BCN monolayer is a semiconductor with a direct bandgap of 0.9 (1.63) eV determined via the Perdew-Burke-Ernzerhof (Heyd-Scuseria-Ernzerhof) functional. The same electron and hole effective masses and mobility values indicate the high recombination rate of electrons and holes. Meanwhile, the BCN monolayer can absorb ultraviolet radiation more effectively than visible light. Due to its interesting physical properties, the novel BCN monolayer could be a rather good candidate material for electro-optical applications.& nbsp;Published under an exclusive license by AIP Publishing
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| 2. |
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| 3. |
- Bafekry, A., et al.
(författare)
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Investigation of vacancy defects and substitutional doping in AlSb monolayer with double layer honeycomb structure: a first-principles calculation
- 2022
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Ingår i: Journal of Physics. - : IOP Publishing Ltd. - 0953-8984 .- 1361-648X. ; 34:6
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Tidskriftsartikel (refereegranskat)abstract
- The experimental knowledge of the AlSb monolayer with double layer honeycomb structure is largely based on the recent publication (Le Qin et al 2021 ACS Nano 15 8184), where this monolayer was recently synthesized. Therefore, the aim of our research is to consequently explore the effects of substitutional doping and vacancy point defects on the electronic and magnetic properties of the novel hexagonal AlSb monolayer. Besides experimental reports, the phonon band structure and cohesive energy calculations confirm the stability of the AlSb monolayer. Its direct bandgap has been estimated to be 0.9 eV via the hybrid functional method, which is smaller than the value of 1.6 eV of bulk material. The majority of vacancy defects and substitutional dopants change the electronic properties of the AlSb monolayer from semiconducting to metallic. Moreover, the Mg-Sb impurity has demonstrated the addition of ferromagnetic behavior to the material. It is revealed through the calculation of formation energy that in Al-rich conditions, the vacant site of V-Sb is the most stable, while in Sb-rich circumstances the point defect of V-Al gets the title. The formation energy has also been calculated for the substitutional dopants, showing relative stability of the defected structures. We undertook this theoretical study to inspire many experimentalists to focus their efforts on AlSb monolayer growth incorporating different impurities. It has been shown here that defect engineering is a powerful tool to tune the properties of novel AlSb two-dimensional monolayer for advanced nanoelectronic applications.
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| 4. |
- Bafekry, A., et al.
(författare)
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Two-dimensional FeTe2 and predicted Janus FeXS (X: Te and Se) monolayers with intrinsic half-metallic character: tunable electronic and magnetic properties via strain and electric field
- 2021
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : ROYAL SOC CHEMISTRY. - 1463-9076 .- 1463-9084. ; 23:42, s. 24336-24343
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Tidskriftsartikel (refereegranskat)abstract
- Driven by the fabrication of bulk and monolayer FeTe2 (ACS Nano, 2020, 14, 11473-11481), we explore the lattice, dynamic stability, electronic and magnetic properties of FeTeS and FeSeS Janus monolayers using density functional theory calculations. The obtained results validate the dynamic and thermal stability of the FeTeS and FeSeS Janus monolayers examined. The electronic structure shows that the FeTe2 bulk yields a total magnetization higher than the FeTe2 monolayer. FeTeS and FeSeS are categorized as ferromagnetic metals due to their bands crossing the Fermi level. So, they can be a good candidate material for spin filter applications. The biaxial compressive strain on the FeTe2 monolayer tunes the bandgap of the spin-down channel in the half-metal phase. By contrast, for FeTeS, the biaxial strain transforms the ferromagnetic metal into a half-metal. The electric field applied to the FeSeS monolayer in a parallel direction transforms the half-metal to a ferromagnetic metal by closing the gap in the spin-down channel.
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| 5. |
- Bafekry, A., et al.
(författare)
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Van der Waals heterostructure of graphene and germanane: tuning the ohmic contact by electrostatic gating and mechanical strain
- 2021
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 23:37, s. 21196-21206
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Tidskriftsartikel (refereegranskat)abstract
- Recent exciting developments in synthesis and properties study of the Germanane (GeH) monolayer have inspired us to investigate the structural and electronic properties of the van der Waals GeH/Graphene (Gr) heterostructure by the first-principle approach. The stability of the GeH/Gr heterostructure is verified by calculating the phonon dispersion curves as well as by thermodynamic binding energy calculations. According to the band structure calculation, the GeH/Gr interface is n-type Ohmic. The effects of different interlayer distances and strains between the layers and the applied electric field on the interface have been investigated to gain insight into the van der Waals heterostructure modifications. An interlayer distance of 2.11 angstrom and compressive strain of 6% alter the contact from Ohmic to Schottky status, while the electric field can tune the GeH/Gr contact as p- or n-type, Ohmic, or Schottky. The average electrostatic potential of GeH/Gr and the Bader charge analysis have been used to explain the results obtained. Our theoretical study could provide a promising approach for improving the electronic performance of GeH/Gr-based nano-rectifiers.
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