| 1. |
- Bahti, Soukaina, et al.
(författare)
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Structures, stabilities, optoelectronic and photocatalytic properties of Janus aluminium mono-chalcogenides Al(Ga, In)STe monolayers
- 2022
-
Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier. - 1386-9477 .- 1873-1759. ; 142
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Tidskriftsartikel (refereegranskat)abstract
- Computational design of new two-dimensional materials constitutes an effective and promising approach in the development and exploration of a wide range of emerging applications such as optoelectronics, photocatalysis, energy storage, and conversion. Within the framework of this work, we systematically investigated for the first time, the structural, stability, optoelectronic, and pho-tocatalytic properties of new predicted Al(Ga, In)STe monolayers derived from Janus Aluminium mono-chalcogenides through Density Functional Theory and Ab-Initio molecular dynamic simulations. After a full optimization of both struc-tures, their dynamics and thermal stability was confirmed through the calculations of phonon spectrum and ab-initio molecular dynamics at a chosen temperature, respectively. Subsequently, the electronic and optical properties were explored and findings revealed that both monolayers exhibit a semiconducting characteristic with a direct and indirect electronic band gap of about 2.23 and 2.69 eV using HSE06 hybrid functional for AlGaSTe and AlInSTe monolayers, re-spectively. Furthermore, the optical absorption indicates a strong absorption of light in the range between 3 and 18 eV. More noticeably, Both Janus monolayers considered exhibiting a promising optical absorption in the visible wavelength region with an absorption coefficient greater than 105 cm−1. In addition, the photocatalytic properties of these structures were investigated by plotting the band edge positions straddle the reduction potential of H2 and the oxidation potential H2O. Based on our results, we conclude that both monolayers offer good thermodynamic stability allowing them to be processed experimentally and can be used as very appropriate candidates for optoelectronics and photocatalytic applications.
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| 2. |
- Behloul, M., et al.
(författare)
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Electronic and magnetic behaviors of (V, Mn), (V, Fe) and (V, Cu) codoped tin carbide : Ab initio and Monte Carlo calculations
- 2022
-
Ingår i: Materials Today. - : Elsevier. - 2214-7853. ; , s. 448-453
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Konferensbidrag (refereegranskat)abstract
- In the present study, we performed ab initio calculations for tin carbide codoped with (V,Mn), (V,Cu) and (V,Fe). The electronic and magnetic properties of tin carbide are calculated by means of density functional theory (DFT). The half metallic ferromagnetic behaviour of dual impurities VMnSnC, VFeSnC and VCuSnC is treated by using the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA). Our results evince that, the stability of ferromagnetism state was induced by the charge state of magnetic impurities, which room temperature ferromagnetic DMS based spintonic is realized. The exchange interactions are obtained from first principles calculations using an Ising model. Our calculation is supported by Monte Carlo simulation based on the heat bath algorithm. We have examined the effects of magnetic parameters for magnetization, internal energy and magnetic susceptibility.
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| 3. |
- Behloul, M., et al.
(författare)
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Ferromagnetism induced by Cr, V single and double impurities doped BN from Ab-initio and Monte Carlo study
- 2018
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Ingår i: COMPUTATIONAL CONDENSED MATTER. - : ELSEVIER SCIENCE BV. - 2352-2143. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Using the Ab initio calculations and Monte Carlo (MC) simulations, we investigate the electronic and magnetic properties of cubic BN compound doped and co-doped with Chromium (Cr) and Vanadium (V) atoms. The calculated electronic band structure and density of states (DOS) of doped BN with single and double impurities can induce localized edge states around Fermi level, leading from semiconductor to half-metal transition. Thereafter, the stability of ferromagnetic (FM) ordering and disordered local magnetic moment (DLM) configurations has been explored. The interesting Curie temperature (T-c), magnetization and susceptibility results for the various concentrations of Chromium (Cr) and Vanadium (V) co-doped (doped) BN suggest a vast exploitation attention in spintronic applications.
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| 4. |
- Behloul, M., et al.
(författare)
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Theoretical investigation of the electronic and magnetic properties of Zn (Fe, Co) Se : Ab initio calculations and Monte Carlo simulations
- 2019
-
Ingår i: Superlattices and Microstructures. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0749-6036 .- 1096-3677. ; 127, s. 66-70
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Tidskriftsartikel (refereegranskat)abstract
- On the basis of spin density functional calculation, the electronic and magnetic properties of ZnSe doped with double impurities Zn1-2xFexCoxSe (x = 0.05) are studied using the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method within the local density approximation (LDA). The half-metallic ferromagnetic nature of (Fe, Co) doped ZnSe is investigated. Therefore the electronic structure and magnetic properties of Zn1-2xFexCoxSe exhibit a half-metallic ferromagnetic character; the stability of ferromagnetic (FM) compared to the disorder local moment (DLM) has been discussed. Our calculation is supported by Monte Carlo simulations (MCS) based on the heat bath algorithm. We have examined the effects of system size L on magnetization, specific heat and magnetic susceptibility. The spin density functional calculation results are in good agreement with the literature, especially for 5% of (Co, Fe) each, which gives the most interesting results.
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| 5. |
- Benhouria, Y., et al.
(författare)
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Carbides-anti-perovskites Mn3(Sn, Zn)C : Potential candidates for an application in magnetic refrigeration
- 2020
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Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier BV. - 1386-9477 .- 1873-1759. ; 124
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the combination of the First-principles density functional theory (DFT) calculations and Monte Carlo (MC) methods are investigated on the structural, magneto-electronic and magneto-caloric properties of the anti-perovskite carbides Mn3XC with X = Sn, Zn. Firstly, the electronic band structure and total/partial density of state of both Mn3SnC and Mn3ZnC are computed and compared to other theoretical and experimental works. Our results reveal that both Mn3SnC and Mn3ZnC structures exhibit a metallic behavior and the valence (VB) and conduction (CB) bands overlap considerably. Additionally, the magnetic and magneto-caloric properties including heat capacity (C), the entropy change (ΔS), adiabatic temperature (ΔT) and the refrigerant capacity (RC) were studied under the magnetic field ranging between 0 and 5 T for both anti-perovskites. Our findings suggest that both anti-perovskite carbide (Mn3SnC and Mn3ZnC) can act as an effective substrate for magnetic refrigeration.
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| 6. |
- Benhouria, Y., et al.
(författare)
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Dielectric Properties and Hysteresis Loops of a Ferroelectric Nanoparticle System Described by the Transverse Ising Model
- 2014
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Ingår i: Journal of Superconductivity and Novel Magnetism. - : Springer Science and Business Media LLC. - 1557-1939 .- 1557-1947. ; 27:9, s. 2153-2162
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we use the effective field theory based on the probability distribution method to investigate the longitudinal and transverse polarizations, susceptibility, pyroelectric coefficient, and the hysteresis behavior of a ferroelectric cubic nanowire. The effects of the core-shell exchange interaction and the core-shell transverse fields on the longitudinal and transverse polarizations, the susceptibility, the pyroelectric coefficient, and the hysteresis loops of the system are examined. Some characteristic phenomena are found in the thermal variations, depending on the physical parameters in the shell and in the core.
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| 7. |
- Benhouria, Y., et al.
(författare)
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Dynamic magneto-caloric effect of a C70 fullerene : Dynamic Monte Carlo
- 2019
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Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier BV. - 1386-9477 .- 1873-1759. ; 108, s. 191-196
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Tidskriftsartikel (refereegranskat)abstract
- Using the dynamicMonte Carlo (DMC) simulation, the dynamic magnetocaloric effect of a ferrimagnetic C70 Fullerene-like structure is studied within the dynamic Ising model under of a magnetic (h(t)) field. The influences of the amplitude (h0) and the frequency (ω) of the h(t) magnetic field and bias field (hb) on the thermal behavior of the dynamic order parameter and the dynamic magnetocaloric properties (the dynamic isothermal ΔSiso(T,h(t)) entropy variation and the dynamic ΔTad (T,h(t)) adiabatic variation of temperature), the dynamic specific heat, the dynamic entropy and as well as the dynamic refrigerant capacity (RC(t)) ferrimagnetic C70 Fullerene-like structure are studied. Our results may be a reference for future experiment and theoretical studies of the nano-clusters.
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| 8. |
- Benhouria, Y., et al.
(författare)
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Dynamic magneto-caloric effect of a multilayer nanographene : Dynamic quantum Monte Carlo
- 2019
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Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier BV. - 1386-9477 .- 1873-1759. ; 105, s. 139-145
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Tidskriftsartikel (refereegranskat)abstract
- Using the dynamic quantum Monte Carlo simulation, the dynamic magnetocaloric effect of a ferromagnetic multilayer nanographene (MNG) is studied within the dynamic Ising model under the applied of a time-dependent oscillating (h(t)) magnetic field. The influence of the amplitude h(0) and the period tau of the h(t) and the transverse field Omega on the thermal behavior of the dynamic order parameter and the dynamic magnetocaloric properties (the dynamic isothermal Delta S-T (T, h(t)) entropy change and the dynamic Delta T-ad (T, h(t)) adiabatic change of temperature), the dynamic specific heat, the dynamic entropy and as well as the dynamic relative cooling power (RCP(t)) ferrimagnetic MNG are studied. Our predicted results may be a reference for future experiment and theoretical studies of the nanostructures.
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| 9. |
- Benhouria, Y., et al.
(författare)
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Examination of the Magnetic Properties of the Triangular Type Mixed spin-(1/2,1) Nanowire
- 2020
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Ingår i: Journal of Superconductivity and Novel Magnetism. - : SPRINGER. - 1557-1939 .- 1557-1947. ; 33:3, s. 817-824
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Tidskriftsartikel (refereegranskat)abstract
- In the presence of the crystal field D/J(Core) and the external magnetic field h/J(Core), using the Monte Carlo (MC) simulation based on the heat bath algorithm and the effective field theory (EFT), the triangular mixed spin nanowire model consisting of a spin-(1/2) core which is encircled by a spin-1 ferrimagnetic surface shell is studied. We have studied the special effects of the core surface and crystal field on the critical and compensation temperatures. Several properties, such as the magnetization, hysteresis behaviors, coercive field, and remanent magnetizations are studied. For the appropriate values of the system parameters, the compensation point and multi-loops are found PACS 05.50. + q; 77.80. Bh.
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| 10. |
- Benhouria, Y., et al.
(författare)
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Hysteresis Behavior and Pyroelectric Properties of Multi-Surface Ferroelectric Thin Films
- 2015
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Ingår i: Zhongguó wùli xuékan. - 0577-9073. ; 53:4
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Tidskriftsartikel (refereegranskat)abstract
- Using the transverse Ising model, we investigate the dielectric properties and the hysteresis behavior of multi-surface ferroelectric (MSF) thin films in the framework of the effective field theory based on the probability distribution technique that accounts for the self-spin correlation functions. The effects of the exchange interactions and the transverse field on the longitudinal and the transverse polarizations, the dielectric susceptibility, the pyroelectric coefficient, and the hysteresis loops are studied. A number of interesting phenomena have been found.
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| 11. |
- Benhouria, Y., et al.
(författare)
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Hysteresis loops and dielectric properties of compositionally graded (Ba,Sr)TiO3 thin films described by the transverse Ising model
- 2016
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Ingår i: Zhongguó wùli xuékan. - : Elsevier BV. - 0577-9073. ; 54:4, s. 533-544
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Tidskriftsartikel (refereegranskat)abstract
- Using the effective field theory with a probability distribution technique that accounts for the self-spin correlations, we apply the transverse spin-1/2 Ising model to study the intrinsic hysteresis of compositionally graded Ba1-xSrxTiO3 (BST) thin films with x decreasing from 0.20 to 0.10 in successive slabs. The random bond model of related parameters is applied to mimic doping. The effects of the thickness, the concentration of Sr, the number of slabs and the temperature on the polarization and the hysteresis are discussed.
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| 12. |
- Benhouria, Y., et al.
(författare)
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Monte Carlo simulation of dielectric properties of a mixed spin-3/2 and spin-5/2 Ising ferrielectric nanowires
- 2017
-
Ingår i: Ferroelectrics (Print). - : TAYLOR & FRANCIS LTD. - 0015-0193 .- 1563-5112. ; 507:1, s. 58-68
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Tidskriftsartikel (refereegranskat)abstract
- Dielectric properties of Ising ferrielectric nanowires with spin-3/2 core and spin-5/2 shell structure are systematically studied by the use of the Monte Carlo simulation in the presence of the external longitudinal electric field. Special focus is given to the effects of the core and shell interactions, the interface coupling and the temperature on the core and shell polarizations, the specific heat, the compensations points, the susceptibility and hysteresis behaviors. Some characteristic behaviors are found, such as the existence of triple hysteresis loops for appropriate values of the system parameters affected by the antiferroelectric interface coupling constant and the temperature. The results are compared with those of recently published works and a qualitatively good agreement is found.
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| 13. |
- Benhouria, Y., et al.
(författare)
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Quantum Monte Carlo study of dynamic magnetic properties of nano-graphene
- 2018
-
Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 460, s. 223-228
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Tidskriftsartikel (refereegranskat)abstract
- Using the Quantum Monte Carlo simulation (QMCS), the dynamic blocking temperature of a nanographene bilayer has been investigated within the framework of the Transverse Ising Model (TIM) with mixed spins, under the existence of the time-dependent oscillating longitudinal magnetic field (h(t) = h(b) + h(0)cos(omega t)) and the transverse field (Omega). The influence of the time-dependent oscillating longitudinal magnetic field, the period of magnetic field (tau) and the transverse field (Omega) on the thermal behavior of the total longitudinal and transverse dynamic order parameters, the total dynamic magnetic susceptibility and the dynamic hysteresis of the nano-graphene bilayer are also studied. As results, we remark the appearance of multiple hysteresis loops and the system exhibits the superparamagnetic behavior at the dynamic blocking temperature.
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| 14. |
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| 15. |
- Benhouria, Y., et al.
(författare)
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Thermodynamic properties and hysteresis behaviors of a mixed spin-3/2 and spin-1/2 Ising double walled ferrielectric nanotubes : A Monte Carlo study
- 2014
-
Ingår i: Superlattices and Microstructures. - : Elsevier BV. - 0749-6036 .- 1096-3677. ; 75, s. 761-774
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Tidskriftsartikel (refereegranskat)abstract
- The hysteresis loops and the thermodynamic properties of a ferroelectric or ferrielectric double walled nanotubes (A and B) are studied within the Ising model with mixed spins (S-A = 3/2 and S-B = 1/2) in the presence of the crystal and the external longitudinal electric fields. We use the Monte Carlo method to investigate the effects of the external electric field, the crystal field and the exchange interactions on the total polarization, susceptibility, specific heat and the internal energy of a double walled nanotubes (DWNTs).
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| 16. |
- Bouhou, Samira, et al.
(författare)
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A Theoretical Study of Hysteresis Behaviors of 2D Mixed Spin-(1/2,1)Ising Nanopaticles
- 2018
-
Ingår i: 2018 6th International Renewable And Sustainable Energy Conference (IRSEC). - : IEEE. - 9781728111827 ; , s. 194-198
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Konferensbidrag (refereegranskat)abstract
- The EffectiveField Theory with correlations (EFT) based on the probability distribution is used to investigate the magnetic hysteresis behaviors of both hexagonal and square 2D nanoparticles consisting of a ferromagnetic spin-1/2 core and a ferromagnetic spin-1 shell. The system parameters such as the ferrimagnetic exchange core/shell interaction, the surface shell exchange coupling and the reduced temperatureare examined on the magnetic hysteresis behaviors. Some interesting results have been found such as multiple hysteresis loop behaviors.
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| 17. |
- Bouhou, S., et al.
(författare)
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Magnetic properties of a single transverse Ising ferrimagnetic nanoparticle
- 2015
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Ingår i: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 456, s. 142-150
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Tidskriftsartikel (refereegranskat)abstract
- Using the effective field theory with a probability distribution technique that accounts for the self-spin correlation function, the thermal and the magnetic properties of a single Ising nanoparticle consisting of a ferromagnetic core, a ferromagnetic surface shell and a ferrimagnetic interface coupling are examined. The effect of the transverse held in the surface shell, the exchange interactions between core/shell and in surface shell on the free energy, thermal magnetization, specific heat and susceptibility are studied. A number of interesting phenomena have been found such as the existence of the compensation phenomenon and the magnetization profiles exhibit P-type, N-type and Q-type behaviors. (C) 2014 Elsevier B.V. All rights reserved.
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| 18. |
- Bouhou, S., et al.
(författare)
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Some hysteresis loop features of 2D magnetic spin-1 Ising nanoparticle : shape lattice and single-ion anisotropy effects
- 2017
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Ingår i: Zhongguó wùli xuékan. - : Elsevier BV. - 0577-9073. ; 55:6, s. 2224-2235
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Tidskriftsartikel (refereegranskat)abstract
- The effects of longitudinal and transverse crystal-fields on the magnetic hysteresis behaviors of 2D spin-1 Ising nanoparticles are investigated, by using the effective-field theory based on the probability distribution technique with correlations. Nanoparticles with hexagonal or square lattice are studied. A number of characteristic phenomena such as triple and quadruple hysteresis loop behaviors have been observed for certain physical parameters, originating from the competitions among the core/shell exchange interaction, anisotropies, temperature and the longitudinal magnetic field. Finally, the obtained results are compared with some experimental and theoretical results.
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| 19. |
- Bouziani, I., et al.
(författare)
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Ab initio study of electronic and optical properties of penta-SiC2 and-SiGeC4 monolayers for solar energy conversion
- 2020
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Ingår i: Superlattices and Microstructures. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0749-6036 .- 1096-3677. ; 142
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Tidskriftsartikel (refereegranskat)abstract
- In the current study, we explore theoretically electronic and optical properties of penta-SiC2 and -SiGeC4 monolayers based on ab initio computations and utilizing modified Becke-Johnson generalized gradient-approximation (mBJ-GGA) within the density functional theory. The calculated results show that both 2D penta-SiC2 and -SiGeC4 are structurally stable, according to their negative formation energy. Furthermore, we have found that the penta-SiC2 and -SiGeC4 semiconductors show indirect and moderate band gaps of 1.75 and 1.62 eV by employing mBJGGA functional, respectively. Also, these systems present sigma- and pi-bond between two nearest neighbor carbon atoms by overlapping sp(2)-sp(2) and p-p orbitals, respectively, as well as an ionic bond between two nearest neighbor Si-C and Ge-C atoms. Additionally, we have shown that the considered compounds exhibit small reflectivity and high absorption peaks in visible region with the shift of absorption edge of 2D penta-SiGeC4 to the low energy visible region due to its small band gap compared to that of 2D penta-SiC2. These findings make both penta-SiC2 and -SiGeC4 monolayer semiconductors promising candidates for photovoltaic technology.
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| 20. |
- Bouziani, Ilyas, et al.
(författare)
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Computational prediction of two-dimensional o-Al2N2 under applied strain for boosting the photocatalytic hydrogen evolution reaction performance
- 2023
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 48:91, s. 35542-35551
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Tidskriftsartikel (refereegranskat)abstract
- Photocatalytic water splitting for clean hydrogen fuel production provides a promising approach to solve the energy and environmental issues. Recently, two-dimensional (2D) photocatalysts have attracted growing interest owing to their short carrier diffusion path, abundant active sites and large surface area. This study explores the photocatalytic performance of 2D orthorhombic dialuminum dinitride (o-Al2N2) using density functional theory. The computational results show that the o-Al2N2 monolayer has a semiconductor character with indirect and moderate bandgap. Moreover, this system exhibits high light absorption in the visible region, referring to its high capacity for harvesting sunlight. Meanwhile, under neutral pH, the band edge positions are suitable to straddle water redox potentials and the hydrogen evolution reaction is energetically favorable to allow hydrogen production on the surface of 2D o-Al2N2 compound. More importantly, the photocatalytic activity of o-Al2N2 monolayer is significantly improved under slight biaxial compressive strain. Therefore, our findings suggest that the o-Al2N2 nanomaterial is a highly efficient 2D photocatalyst for hydrogen production via water splitting under neutral pH.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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| 21. |
- Bouziani, I, et al.
(författare)
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Electronic and optical properties of ZnO nanosheet doped and codoped with Be and/or Mg for ultraviolet optoelectronic technologies : density functional calculations
- 2020
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Ingår i: Physica Scripta. - : IOP PUBLISHING LTD. - 0031-8949 .- 1402-4896. ; 95:1
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Tidskriftsartikel (refereegranskat)abstract
- Theoretically, the density functional calculations have been effectuated for investigating electronic and optical properties of zinc oxide nanosheet doped and codoped with Be and/or Mg utilizing the generalized gradient approximation modified Becke-Johnson (GGA-mBJ) approach. The computed results show that the ZnBeO, ZnMgO and ZnBeMgO in nanosheet structure, referring to their low formation energy values, are more stable than those in bulk one. Furthermore, the bandgap of ZnO monolayer can be effectively modulated through substitution of Zn atoms by Be and/or Mg. In addition to that, by incorporating Be and/or Mg, the absorption peaks of ZnO nanosheet shift into the shorter UV-wavelength side as well as its reflectivity becomes lower. These results indicate that doping and codoping process of ZnO monolayer with Be and/or Mg are two efficient ways to modulate electronic and optical properties for ultraviolet optoelectronic technologies.
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| 22. |
- Bouziani, I., et al.
(författare)
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Electronic, optical and thermoelectric properties of two-dimensional pentagonal SiGeC4 nanosheet for photovoltaic applications : First-principles calculations
- 2021
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Ingår i: Superlattices and Microstructures. - : Elsevier. - 0749-6036 .- 1096-3677. ; 158
-
Tidskriftsartikel (refereegranskat)abstract
- In this theoretical study, based on the density functional theory, we investigate the electronic, optical and thermoelectric properties of SiGeC4 nanosheet, within the framework of mBJ-GGA approximation (modified Becke-Johnson generalized gradient approximation). The calculated results indicate that the two-dimensional SiGeC4 compound is energetically, dynamically, thermally and mechanically stable in the pentagonal structure and shows semiconductor character with indirect and moderate bandgap. Also, it is found that this two-dimensional system presents high absorption and low reflectivity as well as high photoconductivity in the visible range. Furthermore, it is shown that the studied compound exhibits good thermoelectric performance with high electrical conductivity and Seebeck coefficient. These results render the twodimensional pentagonal SiGeC4 nanosheet as strong absorber layer candidate in the next generation of photovoltaic devices.
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| 23. |
- Bouziani, Ilyas, et al.
(författare)
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Janus Ga2SeTe and In2SeTe nanosheets : Excellent photocatalysts for hydrogen production under neutral pH
- 2023
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 48:43, s. 16358-16369
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Tidskriftsartikel (refereegranskat)abstract
- In the past few years, Janus nanosheets have attracted much interest according to their specific structure and considerable potential to address the energy and environmental issues. Herein, the electronic, optical and photocatalytic properties of two-dimensional Janus Ga2SeTe and In2SeTe have been studied using ab-initio computations based on the density functional theory. The obtained results show that these nanomaterials exhibit a semiconductor behavior with direct and moderate bandgaps using hybrid HSE06 func-tional. Subsequently, the understudied compounds present suitable optical conductivity, absorption, transmission and reflectivity for water splitting under the ultraviolet-visible light irradiation. Interestingly, the band edge positions of Janus Ga2SeTe and In2SeTe excellently straddle the redox potentials of water under neutral pH. Additionally, the free energy values for the formation of H2 from H adsorbed on the Ga2SeTe and In2SeTe com-pounds are respectively 1.304eV and 0.976eV at pH = 7. More excitingly, the present study proposes strain engineering approach to improve the photocatalytic performance of the Janus Ga2SeTe and In2SeTe monolayers. Specifically, the investigated semiconductors show more appropriate band edge alignment and better hydrogen evolution reaction ac-tivity under biaxial tensile strain, which fulfil the water splitting requirements at neutral pH conditions. Our findings conclude that the Janus Ga2SeTe and In2SeTe nanosheets are promising candidates for photocatalytic hydrogen production.
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| 24. |
- Bouziani, I., et al.
(författare)
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Magnetoelectronic properties of GaN codoped with (V, Mn) impurities for spintronic devices : Ab-initio and Monte Carlo studies
- 2018
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Ingår i: Physica A. - : ELSEVIER SCIENCE BV. - 0378-4371 .- 1873-2119. ; 512, s. 1249-1259
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we investigate the Magnetoelectronic properties of (V, Mn) codoped GaN using first principles calculations (FPCs) for the spintronic applications. We have obtained the ferromagnetic behavior in (Ga, V)N codoped with Mn atoms, which is believed to be caused by the double exchange mechanism. Moreover, it is observed that our system is halfmetallic at the Fermi level, with 100% spin polarization. The total magnetic moment of (V, Mn) codoped GaN is mainly originated from the V and Mn atoms, and the magnetic moment of V impurities rises with the concentration of V atoms while keeping constant that of the Mn atoms. In addition to that, the exchange coupling is obtained from FPCs and using the Ising model. The Monte Carlo method founded on the Heat Bath algorithm support our FPCs, by investigating the influence of the addition of Mn impurities to (Ga, V)N compound on the critical temperature T-C(MC), the magnetization per site M, the magnetic susceptibility chi and the specific heat C-V. We have found that T-C(MC) is above room temperature as well as the stability of the ferromagnetic state in (Ga, V)N becomes more important after the inclusion of the Manganese.
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| 25. |
- Bouziani, I., et al.
(författare)
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Magnetoelectronic properties of Vanadium impurities co-doped (Cd, Cr)Te compound for spintronic devices : First principles calculations and Monte Carlo simulation
- 2018
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Ingår i: Journal of Magnetism and Magnetic Materials. - : ELSEVIER SCIENCE BV. - 0304-8853 .- 1873-4766. ; 466, s. 420-429
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Tidskriftsartikel (refereegranskat)abstract
- We have applied the first-principles calculations to investigate magnetoelectronic properties of Vanadium impurities co-doped (Cd, Cr)Te compound for spintronic devices. The ferromagnetic (FM) nature in (Cd, Cr)Te compound co-doped with V atoms has been found, and the mechanism responsible for this behavior has been considered to be the double exchange. Moreover, the Curie-temperature calculation reveals that the stability's field of the FM-phase rises with rising both the concentration of Cr and V atoms above ambient temperature. This system presents the half-metallic character where its polarization of spin is total at the Fermi level, and its total magnetic moment is principally induced by Cr and V elements. The spin-orbit coupling (SOC) typically play an important role in the electronic structure calculations due to both the concentration of Cr and V impurities. In addition to that, our results have been confirmed by the calculation of magnetization and susceptibility using the Monte Carlo simulation.
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| 26. |
- Bouziani, I., et al.
(författare)
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Two-dimensional Janus Sn2SSe and SnGeS2 semiconductors as strong absorber candidates for photovoltaic solar cells : First principles computations
- 2021
-
Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier. - 1386-9477 .- 1873-1759. ; 134
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional materials provide new opportunities for the next generation of effective and ultrathin photovoltaic solar cells. Herein, we propose Janus monolayers of Tin monochalcogenides, especially Janus Sn2SSe (type TA) and SnGeS2 (type TB) nanosheets, as strong absorber candidates for solar energy conversion, referring to their excellent electronic and optical properties. Interestingly, based on the first-principles computations, both Janus Sn2SSe and SnGeS2 monolayers possess semiconductor character with indirect and moderate band gaps of 1.60 and 1.61 eV, respectively. Accordingly, the considered systems, Sn2SSe and SnGeS2 single-layers, have high absorption coefficient, reaching up to 49.7 and 62.5 mu m(-1), high optical conductivity of about 4513 and 3559 Omega(-1)cm(-1), as well as low reflectivity never exceed 34.6 and 38.5 % in visible region, respectively. Additionally, the maximum photovoltaic efficiency of single-junction solar cells based on SnGeS2 and Sn2SSe nanosheets can reach as high as 27.47 % and 28.12 %, respectively. The present outstanding results would motivate both theoretical and experimental researchers to deepen the study of the potential applications of twodimensional Janus materials based on Tin monochalcogenides in solar cell technology.
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| 27. |
- Chafai, A., et al.
(författare)
-
Binding energy of an exciton in a GaN/AlN nanodot : Role of size and external electric field
- 2019
-
Ingår i: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 559, s. 23-28
-
Tidskriftsartikel (refereegranskat)abstract
- We report the impact of an external electric field on the energy spectrum of an exciton inside a spherical shaped GaN/AlN core/shell nanodot. The modulation of the confined exciton lowest state energy by the nanodot size is also treated. Our theoretical approach, based on a variational calculation, predicts a remarkable decrease in the exciton's energy when the electric field is switched on. Furthermore, our investigation shows that for a fixed nanodot size, the energy redshift is a unique function of the external electric field strength. On the other hand, it was observed that as the nanodot size increases the lowest exciton energy decreases and vice versa.
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| 28. |
- Chafai, A., et al.
(författare)
-
Hydrogenic donor in a CdSe/CdS quantum dot : Effect of electric field strength, nanodot shape and dielectric environment on the energy spectrum
- 2018
-
Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier BV. - 1386-9477 .- 1873-1759. ; 104, s. 29-35
-
Tidskriftsartikel (refereegranskat)abstract
- The impact of an external electric field on the binding energy of a single donor impurity was examined within the effective-mass approach by deploying a variational calculation. The discontinuity of the permittivity, epsilon(r), and of the particle effective mass, m(i)*(r), at the nanosystem boundaries was considered. Using the image charge approach, the impact of the surrounding medium on the shallow donor energy spectrum was also taken into account. Our theoretical investigation shows that, for zero electric field and when the shell thickness is taken constant, the increase of the core material size leads to decrease the single donor correlation energy. Further, for a fixed core material size the energy decreases quickly when the shell thickness moves from 0 to 1 nm, while it decreases very slowly when the shell thickness is ranged between 1 nm and 4 nm. On the other hand, we have established that when we turn on an external electric field, the probability density of confined particles tends to move towards the nanodot border which naturally shifts the energy spectrum to lower energies (redshift). It was also obtained that the donor Stark shift depends not only on the nanodot size, but also on the surrounding medium.
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| 29. |
- El Hamri, M., et al.
(författare)
-
Investigation of the surface shell effects on the magnetic properties of a transverse antiferromagnetic Ising nanocube
- 2015
-
Ingår i: Superlattices and Microstructures. - : Elsevier BV. - 0749-6036 .- 1096-3677. ; 80, s. 151-168
-
Tidskriftsartikel (refereegranskat)abstract
- The effective-field theory (EFT) with correlations based on the probability distribution technique has been used to study the magnetic properties of an antiferromagnetic cubic nanoparticle (nanocube). We have found that the surface shell parameters have strong effects on the compensation temperature, the magnetization profiles, coercivity, the shape and the number of the hysteresis loops for certain parameters. The effect of reduced temperature has also been examined on the hysteresis loops.
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| 30. |
- El Hamri, M., et al.
(författare)
-
Magnetic behaviors of a transverse spin-1/2 Ising cubic nanowire with core/shell structure
- 2017
-
Ingår i: Physica. B, Condensed matter. - : Elsevier. - 0921-4526 .- 1873-2135. ; 507, s. 51-60
-
Tidskriftsartikel (refereegranskat)abstract
- The surface shell exchange coupling effect on the magnetic properties (surface shell, core, total longitudinal and total transverse magnetizations, susceptibility, phase diagram and hysteresis loops) of a transverse spin-1/2 Ising cubic nanowire is investigated, in the present work, by employing the effective-field theory based on the probability distribution technique with correlations, for both ferro-and antiferromagnetic cases. We have found that this parameter has a strong effect on the magnetic properties in both cases. In the ferromagnetic case, the total longitudinal magnetization curves display Q-and S-type behaviors and the hysteresis loop has just one loop, whereas in the antiferromagnetic case, the N-type behavior, in which one compensation temperature appears below the critical temperature, exists in the total longitudinal magnetization curve versus reduced temperature, and triple hysteresis loops are found. The effect of applied field is also investigated on the total longitudinal magnetization for the both cases, and we have found that a large applied field value can overcome the antiferromagnetic coupling leading to a ferromagnetic-like behavior.
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| 31. |
- El Hamri, M., et al.
(författare)
-
Magnetic properties of a diluted spin-1/2 Ising nanocube
- 2016
-
Ingår i: Physica A. - : Elsevier BV. - 0378-4371 .- 1873-2119. ; 443, s. 385-398
-
Tidskriftsartikel (refereegranskat)abstract
- The effective-field theory with correlations based on the probability distribution technique is used to investigate the magnetic properties of a diluted Ising nanocube consisting of a ferromagnetic spin-1/2 core which is interacting antiferromagnetically with a ferromagnetic spin-1/2 surface shell. The effect of the concentration of magnetic atoms is examined. A number of interesting phenomena have been found such as the existence of the compensation temperature and triple hysteresis loops.
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| 32. |
- El Hamri, M., et al.
(författare)
-
Magnetic Properties of a Diluted Transverse Spin-1 Ising Nanocube with a Longitudinal Crystal-Field
- 2017
-
Ingår i: INTERNATIONAL SYMPOSIUM ON CLUSTERS AND NANOMATERIALS. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510608429
-
Konferensbidrag (refereegranskat)abstract
- In the present work, the effective field theory with correlations based on the probability distribution technique has been used to investigate the effect of the surface shell longitudinal cristal field on the magnetic properties of a diluted antiferromagnetic spin-1 Ising nanocube particle. This effect has also been studied on the hysteresis loops of the system. It is found that this parameter has a strong effect on the magnetization profiles, compensation temperature, coercive field and remanent magnetization.
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| 33. |
- El Hamri, M., et al.
(författare)
-
Phase diagrams of a transverse cubic nanowire with diluted surface shell
- 2016
-
Ingår i: Applied Physics A. - : Springer Science and Business Media LLC. - 0947-8396 .- 1432-0630. ; 122:3
-
Tidskriftsartikel (refereegranskat)abstract
- The effective-field theory with correlations based on the probability distribution technique has been used to investigate the phase diagrams (critical and compensation temperatures) of a transverse antiferromagnetic spin-1/2 Ising cubic nanowire with diluted surface shell. It is found that the phase diagrams of the system are strongly affected by the surface shell parameters. Indeed, two compensation points appear for certain values of Hamiltonian parameters, and the range of appearance of these latter points depends strongly on the surface shell transverse field.
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| 34. |
- El Hamri, M., et al.
(författare)
-
Some characteristic behaviours of a spin-1/2 Ising nanoparticle
- 2016
-
Ingår i: 3Rd Euro-Mediterranean Conference On Materials And Renewable Energies (Emcmre-3). - : IOP PUBLISHING LTD.
-
Konferensbidrag (refereegranskat)abstract
- By using the effective-field theory with correlations based on the probability distribution technique; the magnetization, susceptibility, internal energy, specific heat and the free energy expressions for a ferromagnetic spin-1/2 Ising nanoparticle have been developed and calculated numerically for different surface shell exchange coupling parameter. A number of interesting phenomena have been observed, depending on the surface shell exchange coupling term.
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| 35. |
- El Hamri, M., et al.
(författare)
-
Thermodynamic Properties of the Core/Shell Antiferromagnetic Ising Nanocube
- 2015
-
Ingår i: Journal of Superconductivity and Novel Magnetism. - : Springer Science and Business Media LLC. - 1557-1939 .- 1557-1947. ; 28:10, s. 3127-3133
-
Tidskriftsartikel (refereegranskat)abstract
- Using the effective field theory with correlations, the effects of the exchange interaction on the thermal behaviors of the total magnetization, internal energy, specific heat, entropy, and free energy of a transverse antiferromagnetic Ising nanocube are investigated. The phase diagram is also calculated and discussed in detail.
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| 36. |
- Haman, Zakaryae, et al.
(författare)
-
Computational identification of efficient 2D Aluminium chalcogenides monolayers for optoelectronics and photocatalysts applications
- 2021
-
Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 556
-
Tidskriftsartikel (refereegranskat)abstract
- The massive consumption of traditional fossil fuel like oil, coal and natural gas has led to serious environmental issues, which drove the search for cleaner renewable energy sources. One such option is photocatalytic water splitting that has attracted much attention as a viable process for the large scale production of hydrogen as a renewable fuel. Within this perspective, we methodically studied the structural, optoelectronic, and photocatalytic properties of two-dimensional aluminum monochalcogenide monolayers with the chemical formula AlX (X = O, S, Se, and Te) based on the framework of Density Functional Theory (DFT). All considered structures are full relaxed and their thermodynamic stabilities are confirmed by computing the phonon spectrum and Ab Initio Molecular Dynamics (AIMD) simulations. The electronic characteristics are also performed on the basis of both exchange correlation functional GGA-PBE and HSE06 in order to obtain the accurate electronic band gap. According to our calculations, all the four monolayers posses indirect band gaps ranging between 1.937 and 2.46 eV. Furthermore, based on desirable electronic band gaps, the optical performance features were further explored including complex refractive index, absorption coefficient and energy loss function by means of the complex dielectric function. It is found that all the four materials present a high absorption coefficient in the visible and Ultra-Violet regions. Finally, the band edge positions of our monolayers straddle the reduction potential of H2 and the oxidation potential H2O. Also, it was found that the Gibbs free energy of 2D AlO monolayer is 0.02 eV at certain applied external electric field and very close to ideal catalysts which suggest that the AlO monolayer is better candidate for hydrogen production. Our findings demonstrate that AlX monolayers are suitable materials for optoelectronics and hydrogen production via photocatalytic water splitting.
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| 37. |
- Haman, Zakaryae, et al.
(författare)
-
Janus Aluminum Oxysulfide Al2OS : A promising 2D direct semiconductor photocatalyst with strong visible light harvesting
- 2022
-
Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 589
-
Tidskriftsartikel (refereegranskat)abstract
- Hydrogen production via solar light-driven water dissociation has been regarded as an artificial and effective process to overcome the environmental problem as well as solving the current energy crisis. In this regard, numerous works have mainly been devoted to developing the appropriate photocatalyst which satisfies the conditions for water splitting and understanding the photocatalysis process. In this study, we propose for the first time the potential application of the two-dimensional Janus aluminum oxysulfide Al2OS as an efficient photocatalyst material for hydrogen-production H-2 through the first-principles calculations. Janus Al2OS monolayer has been designed from the parental binary aluminum sulfide AlS by substituting one sub-layer of sulfide atoms (S) to oxygen atoms (O). The electronic properties of the pristine AlS and the derived Janus Al2OS were computed using GGA-PBE and HSE06 functionals. According to the band structure, AlS monolayer shows a semiconductor behavior with an indirect bandgap of 2.14 eV whereas, the Janus Al2OS exhibits a direct bandgap of 1.579 eV. Motivated by the desirable bandgap of the Janus Al2OS, the absorption-coefficient of Janus Al2OS shows strong visible light harvesting compared to the parental AlS. Furthermore, the photocatalytic performance of Al2OS has been investigated. Our calculations demonstrate that the band edge position of Al2OS is suitable for the hydrogen evolution reaction (HER). More importantly, based on the reaction coordinate, it was found that the Gibbs free-energy Delta G(H*) of Al2OS is 0.97 eV which is smaller than of the two-dimensional Janus Ga2XY (X, Y = S, Se, Te with X not equal Y) reported recently. Moreover, this value decreases from 0.97 eV to 0.69 eV under 0.5 V/angstrom of an external electrical field. Our results indicate that Janus Al2OS fulfills the fundamental requirements for efficient photo-catalyst under visible light and provides new guidance for hydrogen-production via water splitting.
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| 38. |
- Haman, Zakaryae, et al.
(författare)
-
Photocatalytic and thermoelectric performance of asymmetrical two-dimensional Janus aluminum chalcogenides
- 2023
-
Ingår i: Journal of Physics. - : IOP Publishing. - 2515-7655. ; 5:3
-
Tidskriftsartikel (refereegranskat)abstract
- Through a density functional theory-driven survey, a comprehensive investigation of two-dimensional (2D) Janus aluminum-based monochalcogenides (Al2XY with X/Y = S, Se, and Te) has been performed within this study. To begin with, it is established that the examined phase, in which the Al-atoms are located at the two inner planes while the (S, Se, and Te)-atoms occupy the two outer planes in the unit cell, are energetically, mechanically, dynamically, and thermally stable. To address the electronic and optical properties, the hybrid function HSE06 has been employed. It is at first revealed that all three monolayers display a semiconducting nature with an indirect band gap ranging from 1.82 to 2.79 eV with a refractive index greater than 1.5, which implies that they would be transparent materials. Furthermore, the monolayers feature strong absorption spectra of around 10(5) cm(-1) within the visible and ultraviolet regions, suggesting their potential use in optoelectronic devices. Concerning the photocatalytic performance, the conduction band-edge positions straddle the hydrogen evolution reaction redox level. Also, it is observed that the computed Gibbs free energy is around 1.15 eV, which is lower and comparable to some recently reported 2D-based Janus monolayers. Additionally, the thermoelectric properties are further investigated and found to offer a large thermal power as well as a high figure of merit (ZT) around 1.03. The aforementioned results strongly suggest that the 2D Janus Al-based monochalcogenide exhibits suitable characteristics as a potential material for high-performance optoelectronic and thermoelectric applications.
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| 39. |
- Haman, Z., et al.
(författare)
-
Structural, electronic and optical properties of two-dimensional Janus transition metal oxides MXO (M = Ti, Hf and Zr; X = S and Se) for photovoltaic and opto-electronic applications
- 2021
-
Ingår i: Physica. B, Condensed matter. - : Elsevier. - 0921-4526 .- 1873-2135. ; 604
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional Janus transition metal dichalcogenides structures have drawn increasing importance due to their remarkable properties for versatile applications in optoelectronic, photo-catalytic, thermo-electricity, piezoelectricity and spintronic. In this Paper, by employing the Ab-initio computations based on the density functional theory, the structural, electronic and optical properties of Janus MXO (M = Ti, Hf and Zr; X = S and Se) mono-layers are investigated utilizing full potential linearized augmented plane waves (FP-LAPW) method. The lattice parameters of the six Janus were computed, which are close to the previous theoretical results. The density of states and the electronic band structures were investigated for the first time using (GGA-PBE) approximation for the potential of the exchange and correlation. The optical parameters like complex dielectric function, refractive index, reflectivity, extinction and absorption coefficients of all Janus were performed. Our results reveal strong absorption coefficient and low reflectivity in the visible and ultraviolet regions, which make them candidates for opto-electronic and photovoltaic applications.
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| 40. |
- Houmad, M., et al.
(författare)
-
Improving the electrical conductivity of Siligraphene SiC7 by strain
- 2019
-
Ingår i: Optik (Stuttgart). - : Elsevier BV. - 0030-4026 .- 1618-1336. ; 177, s. 118-122
-
Tidskriftsartikel (refereegranskat)abstract
- Using the 1st principle calculations founded on Density Functional Theory (DFT), we examined the strain effect of band gap (BG) and electrical property (EP) of Siligraphene (g-SiC7) under biaxial strains (Compressive and tensile) using Generalized Gradient Approximation (GGA). We found that the BG of g-SiC7 was decreasing as function of the strain and we remarked that the electrical conductivity of g-SiC7 under biaxial strains become important of 6% for tension effect. For the compressive, we obtained an increase for all compressive applying, but we remarked the higher and lower values are successively -2% and -6%. Last not least, we deduced that it's possible to increase the electrical conductivity of g-SiC7. Also, this material can be used in solar cell applications and for photo-voltaic (PV) applications as a light donor material.
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| 41. |
- Htoutou, K., et al.
(författare)
-
The Magnetic Properties of the Mixed Ferrimagnetic Ising System with Random Crystal Field
- 2017
-
Ingår i: Journal of Superconductivity and Novel Magnetism. - : SPRINGER. - 1557-1939 .- 1557-1947. ; 30:5, s. 1247-1256
-
Tidskriftsartikel (refereegranskat)abstract
- Using the effective-field theory EFT based on the probability distribution technique, the effect of the random crystal field on the magnetic properties of ferrimagnetic mixed Ising system with both spin-1 and spin-3/2 is investigated. The critical temperature is discussed as function of different strengths of the random crystal field and the exchange interactions. The phase diagrams are calculated numerically for a square lattice and the number of characteristic phenomena, such as the tricritical point are found. Our results are different to that reported in Souza et al. (Physica A 444, 589-600 2016).
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| 42. |
- Khossossi, Nabil, et al.
(författare)
-
Ab initio study of a 2D h-BAs monolayer : a promising anode material for alkali-metal ion batteries
- 2019
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : ROYAL SOC CHEMISTRY. - 1463-9076 .- 1463-9084. ; 21:33, s. 18328-18337
-
Tidskriftsartikel (refereegranskat)abstract
- The selection of a suitable two dimensional anode material is one of the key steps in the development of alkali metal ion batteries to achieve superior performance with an ultrahigh rate of charging/discharging capability. Here, we have used state of the art density functional theory (DFT) to explore the feasibility of two dimensional (2D) honeycomb boron arsenide (h-BAs) as a potential anode for alkali-metal (Li/Na/K)-ion batteries. The structural and dynamic stability has been confirmed from the formation energy and the non-negative phonon frequency. The h-BAs monolayer exhibits negative adsorption-energy values of -0.422, -0.321 and -0.814 eV, for the Li, Na, and K-ions, respectively. Subsequently, during the charging process the adsorption-energy increases considerably without an energy-barrier when any of the A-atoms achieve a crucial distance (similar to 8 angstrom). In addition, it has been observed that insertion of the mono alkali metal atom into the h-BAs surface results in the semi-conducting nature of the monolayer being transformed into a metallic-state. The low energy barriers for Li (0.522 eV), Na (0.248), and K (0.204 eV) active ion migration imply high diffusion over the h-BAs surface, hence suggesting it has a high charge/discharge capability. Moreover, we have obtained low average operating voltages of 0.49 V (Li), 0.35 V (Na) and 0.26 V (K) and high theoretical capacities of 522.08 mA h g(-1) (for Li and Na) and 209.46 mA h g(-1) (for K) in this study. The aforementioned findings indicate that a h-BAs monolayer could be a promising anode material in the search for low cost and high performance alkali metal ion batteries.
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| 43. |
- Khossossi, Nabil, et al.
(författare)
-
High-Specific-Capacity and High-Performing Post-Lithium-Ion Battery Anode over 2D Black Arsenic Phosphorus
- 2021
-
Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 4:8, s. 7900-7910
-
Tidskriftsartikel (refereegranskat)abstract
- Nowadays, secondary batteries based on sodium (Na), potassium (K), and magnesium (Mg) stimulate curiosity as eventually high-availability, nontoxic, and eco-friendly alternatives of lithium-ion batteries (LIBs). Against this background, a spate of studies has been carried out over the past few years on anode materials suitable for post-lithium-ion battery (PLIBs), in particular sodium-, potassium- and magnesium-ion batteries. Here, we have consistently studied the efficiency of a 2D alpha-phase arsenic phosphorus (alpha-AsP) as anodes through density functional theory (DFT) basin-hopping Monte Carlo algorithm (BHMC) and ab initio molecular dynamics (AIMD) calculations. Our findings show that alpha-AsP is an optimal anode material with very high stabilities, high binding strength, intrinsic metallic characteristic after (Na/K/Mg) adsorption, theoretical specific capacity, and ultralow ion diffusion barriers. The ultralow energy barriers are found to be 0.066 eV (Na), 0.043 eV (K), and 0.058 eV (Mg), inferior to that of the widely investigated MXene materials. During the charging process, a wide (Na+/K+/Mg2+) concentration storage from which a high specific capacity of 759.24/506.16/253.08 mAh/g for Na/K/Mg ions was achieved with average operating voltages of 0.84, 0.93, and 0.52 V, respectively. The above results provide valuable insights for the experimental setup of outstanding anode material for post-Li-ion battery.
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| 44. |
- Khossossi, Nabil, et al.
(författare)
-
Hydrogen storage characteristics of Li and Na decorated 2D boron phosphide
- 2020
-
Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry (RSC). - 2398-4902. ; 4:9, s. 4538-4546
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Solid-state systems serve as a candidate for clean energy applications driven by current technological demands. In this effort, density functional theory (DFT) has become a valuable asset to investigate the intrinsic electronic properties and holds a substantial promise for guiding the discovery of new materials. Herein, we have investigated the Li and Na decorated 2D boron phosphide (BP) monolayer as a potential candidate for hydrogen storage due to its lightweight and structural stability. Li and Na adatoms prefer to adsorb at the center of the hexagon with the binding energies 0.36 and 0.26 eV, respectively. The thermodynamic stabilities of BP monolayer in cases of 4Li@BP and 4Na@BP systems were evaluated at room temperature using ab initio molecular dynamics (AIMD) simulations. The study of the electronic structure revealed that the semiconducting BP sheets become metallic after the adatom adsorption. It was found that the dispersed Li and Na atoms on the monolayer surface significantly increase both the hydrogen binding energies and the hydrogen storage capacities. With one-sided coverage of Li and Na atoms, four H2 molecules were adsorbed with a gravimetric capacity of 4.917 and 4.558 wt%, respectively. For double-sided adatom coverage, a total of 16H2 molecules was captured around 4Li@BP and 4Na@BP complex with a gravimetric capacity of 7.402 and 6.446 wt%, respectively. These results suggest that boron phosphide (BP) can act as an effective substrate for H2 storage by carefully engineering it with metal decoration.
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| 45. |
- Khossossi, Nabil, et al.
(författare)
-
Rational Design of 2D h-BAs Monolayer as Advanced Sulfur Host for High Energy Density Li-S Batteries
- 2020
-
Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 3:8, s. 7306-7317
-
Tidskriftsartikel (refereegranskat)abstract
- The emergence of compact lithium-sulfur (Li-S) batteries with improved performances is becoming one of the most desirable aspects of future energy technologies. Beyond Li-ion batteries, Li-S is of great relevance to follow as it adapts to the specificity of each application. It is among the most suitable elements for high-performance energy storage systems, given its high theoretical capacity (1674 mA h g(-1)) and energy density (2600 W h kg(-1)) relative to Li-ion batteries (300 W h kg(-1)). Nevertheless, the high-cell polarization and the shuttle effect constitute an enormous challenge toward the concrete applications of Li-S batteries. In the framework of this work, density functional theory calculations have been carried out to analyze the potential of h-BAs nanosheets as a promising host material for Li-S batteries. Binding and electronic characteristics of lithium polysulfides (LiPSs) adsorbed on h-BAs surface have been explored. Reported findings highlight the potential of the hBAs monolayer as a moderate host material, given that the binding energies of different LiPSs vary from 0.47 to 3.55 eV. More detailed analysis of the complex binding mechanisms is carried out by investigating the components of van der Waals physical/chemical interactions. The defected surface of the h-BAs monolayer has optimum binding energies with LiPSs for Li-S batteries. All these findings provide valuable insights into the binding and electronic characteristics of the h-BAs monolayer as a moderate host material for Li-S batteries.
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| 46. |
- Khossossi, Nabil, et al.
(författare)
-
Recent progress of defect chemistry on 2D materials for advanced battery anodes
- 2020
-
Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 15:21, s. 3390-3404
-
Forskningsöversikt (refereegranskat)abstract
- The rational design of anode materials plays a significant factor in harnessing energy storage. With an in-depth insight into the relationships and mechanisms that underlie the charge and discharge process of two-dimensional (2D) anode materials. The efficiency of rechargeable batteries has significantly been improved through the implementation of defect chemistry on anode materials. This mini review highlights the recent progress achieved in defect chemistry on 2D materials for advanced rechargeable battery electrodes, including vacancies, chemical functionalization, grain boundary, Stone Wales defects, holes and cracks, folding and wrinkling, layered von der Waals (vdW) heterostructure in 2D materials. The defect chemistry on 2D materials provides numerous features such as a more active adsorption sites, great adsorption energy, better ions-diffusion and therefore higher ion storage, which enhances the efficiency of the battery electrode.
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| 47. |
- Khossossi, Nabil, et al.
(författare)
-
Revealing the superlative electrochemical properties of o-B2N2 monolayer in Lithium/Sodium-ion batteries
- 2022
-
Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 96
-
Tidskriftsartikel (refereegranskat)abstract
- Promising flexible electrochemical energy storage systems (EESSs) are currently drawing considerable attention for their tremendous prospective end-use in portable self-powered electronic devices, including roll-up displays, and "smart "garments outfitted with piezoelectric patches to harvest energy from body movement. However, the lack of suitable battery electrodes that provides a specific electrochemical performance has made further development of these technologies challenging. Two-dimensional (2D) lightweight and flexible materials with outstanding physical and chemical properties, including mechanical strengths, hydrophilic surfaces, high surface metal diffusivity, and good conductivity, have been identified as a potential prospect for battery electrodes. In this study, taking a new 2D boron nitride allotrope, namely 2D orthorhombic diboron dinitride monolayer (o-B2N2) as representatives, we systematically explored several influencing factors, including electronic, mechanical, and their electrochemical properties (e.g., binding strength, ionic mobility, equilibrium voltage, and theoretical capacity). Considering potential charge-transfer polarization, we employed a charged electrode model to simulate ionic mobility and found ionic mobility has a unique dependence on the surface atomic configuration influenced by bond length, valence electron number, electrical conductivity, excellent ionic mobility, low equilibrium voltage with excellent stability, good flexibility, and extremely superior theoretical capacity, up to 8.7 times higher than that of widely commercialized graphite (3239.74 mAh g(-1) Vs 372 mAh g(-1)) in case of Li-ion batteries and 2159.83 mAh g(-1) in case of Na-ion batteries, indicating that the new predicted 2D o-B2N2 monolayer possess the capability to be ideal flexible anode materials for Lithium and Sodium-ion battery. Our finding provides valuable insights for experimental explorations of flexible anode candidates based on 2D o-B2N2 monolayer.
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| 48. |
- Khossossi, Nabil, et al.
(författare)
-
Thermodynamics and kinetics of 2D g-GeC monolayer as an anode materials for Li/Na-ion batteries
- 2021
-
Ingår i: Journal of Power Sources. - : Elsevier B.V.. - 0378-7753 .- 1873-2755. ; 485
-
Tidskriftsartikel (refereegranskat)abstract
- Development of high capacity anode materials is one of the essential strategies for next-generation high-performance Li/Na-ion batteries. Rational design, using density functional theory, can expedite the discovery of these anode materials. Here, we propose a new anode material, germanium carbide, g-GeC, for Li/Na-ion batteries. Our results show that g-GeC possesses both benefits of the high stability of graphene and the strong interaction between Li/Na and germanene. The single-layer germanium carbide, g-GeC, can be lithiated/sodiated on both sides yielding Li2GeC and Na2GeC with a storage capacity as high as 633 mA h/g. Besides germagraphene's 2D honeycomb structure, fast charge transfer, and high (Li/Na)-ion diffusion and negligible volume change further enhance the anode performance. These findings provide valuable insights into the electronic characteristics of newly predicted 2D g-GeC nanomaterial as a promising anode for (Li/Na)-ion batteries.
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| 49. |
- Khossossi, Nabil, et al.
(författare)
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Unveiling the catalytic potential of two-dimensional boron nitride in lithium-sulfur batteries
- 2024
-
Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 479
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Tidskriftsartikel (refereegranskat)abstract
- Lithium-sulfur (Li-S) batteries, renowned for their potential high energy density, have attracted attention due to their use of earth-abundant elements. However, a significant challenge lies in developing suitable materials for both lithium-based anodes, which are less prone to lithium dendrite formation, and sulfur-based cathodes. This obstacle has hindered their widespread commercial viability. In this study, we present a novel sulfur host material in the form of a two-dimensional semiconductor boron nitride framework, specifically the 2D orthorhombic diboron dinitride (o-B2N2). The inherent conductivity of o-B2N2 mitigates the insulating nature often observed in sulfur-based electrodes. Notably, the o-B2N2 surface demonstrates a high binding affinity for long-chain Li-polysulfides, leading to a significant reduction in their dissolution into the DME/DOL electrolytes. Furthermore, the preferential deposition of Li2S on the o-B2N2 surface expedites the kinetics of the lithium polysulfide redox reactions. Additionally, our investigations have revealed a catalytic mechanism on the o-B2N2 surface, significantly reducing the free energy barriers for various sulfur reduction reactions. Consequently, the integration of o-B2N2 as a host cathode material for Li-S batteries holds great promise in suppressing the shuttle effect of lithium polysulfides and ultimately enhancing the overall battery performance. This represents a practical advancement for the application of Li-S batteries.
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- Kibbou, Moussa, et al.
(författare)
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Advancing photovoltaics and optoelectronics : Exploring the superior performance of lead-free halide perovskites
- 2024
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Ingår i: Optical materials (Amsterdam). - : Elsevier. - 0925-3467 .- 1873-1252. ; 147
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Tidskriftsartikel (refereegranskat)abstract
- One of the emerging directions that has greatly advanced the fields of photovoltaics and optoelectronics is the development of lead-free inorganic halide perovskites. In this study, ab-initio methods were employed to forecast the structural, electronic, and optical behavior of the perovskite materials Cs2Cu+Al3+X6 (where X represents Cl or Br). The analyses conducted have revealed the exceptional structural characteristics of these compounds. The electronic band structure and density of states were computed using the PBE method with the mBJ potential. The direct bandgaps of Cs2CuAlCl6 and Cs(2)CuAlBr(6 )were determined to be 1.35 eV and 0.93 eV, respectively. This suitable electrical bandgap results in high visible-light absorption. As a result, the optical characteristics exhibit a significant absorption coefficient (alpha(omega) approximate to 1.1 x 10(5) cm(-1) for Cs2CuAlBr6 and 0.77 x10(5) cm(-1) for Cs2CuAlCl6), substantial conductivity, and negligible reflectivity (R(omega) < 10%). These attributes render Cs(2)CuAlCl(6 )and Cs2CuAlBr6 semiconductors highly appealing for optoelectronic applications. The maximum spectral light conversion efficiency under AM1.5G solar irradiation was assessed by altering the thickness of the structures. The results reveal that the chlorinated perovskite achieves a slightly higher efficiency of 32.72%, whereas the brominated perovskite reaches an efficiency of 29.31%. Despite their remarkably advantageous bandgaps, limited reflectivity, and impressive efficiency, environmentally friendly halide perovskite compounds hold promise as renewable energy conversion materials. This suggests the potential for substantial enhancements in solar cell performance. Furthermore, employing the finite element (FE) method, we performed calculations to assess carrier generation within a specially engineered solar cell structure comprising an environmentally friendly multilayer (CH3NH3SnI3 and Cs2CuAlX6). Our discoveries unveiled an exceptionally elevated total generation rate at the interfaces between CH3NH3SnI3 and Cs2CuAlX6, reaching approximately 2.5 x 10(29) m(-3)/s. These findings offer novel perspectives that contribute to the research community and hold the potential to advance future solar cell systems.
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