Papers by Souraya Goumri-Said
Various metal complexes are nowadays used in anticancer therapy and organo-metallurgists to devel... more Various metal complexes are nowadays used in anticancer therapy and organo-metallurgists to develop drugs of future. The low cytotoxicity of ferrocene and its malleability have made it an interest anticancer agent. We report a theoretical modeling and computational study of the ferrocene-substituted dithio-o-carborane conjugate in order to understand it structure and control its properties for futur purposes. It is foundthat the ferrocene is a semiconductor with large bandgap, which may its optical spectrum for special role depending on the environment.
Fundamental Investigations of Fermi Surface and Optoelectronic Properties of Pyrochlore Oxide Superconductor (KOs2O6): GGA+ U+ SOC and DFT
We employed first-principle calculations techniques to explore the optoelectronic properties of p... more We employed first-principle calculations techniques to explore the optoelectronic properties of pyrochlore oxide superconductor named KOs2O6. Due to the existence of localized f and d-states in the electronic configuration of Osmium element, the spin orbit coupling and GGA+U approach were considered in computation in order to describe correctly the d-d coupling. KOs2O6 is a metallic and exhibit a large electrical conductivity as found from Fermi surface. The calculated optoelectronic properties have explored the real and the imaginary parts of the dielectric constant along with the other related optical properties like the refractive index, energy loss function and the absorption along with the reflectivity.
Development of alternate counter electrode for the dye-sensitized solar cell (DSSC) using simple ... more Development of alternate counter electrode for the dye-sensitized solar cell (DSSC) using simple and single method are the major focus of the research to resolve problems related to the platinum (Pt)-based counter electrode. In the present work, NiCo2S4 based counter electrode has been directly developed on the fluorine-doped tin oxide coated glass substrate (FTO) using one step and simple hydrothermal method. The prepared NiCo2S4@FTO electrode was characterized by the range of spectroscopic and microscopic techniques as well as further assembled in the DSSC device in order to evaluate the electrode performance. The NiCo2S4 counter electrode exhibited the 6.53% photovoltaic performance in the assembled DSSC which is almost similar to the benchmark Pt based counter electrode (6.88%) under similar experimental conditions. The excellent performance of the elected NiCo2S4@FTO electrode could be due to the high electrocatalytic activity towards the reduction of the I3− to I− and smaller ...
First-principles investigation of electronic structure and magnetic properties in ferromagnetic Ga 1−x Mn x N and Al 1−x Mn x N
In this paper, we present theoretical investigations of the electronic and magnetic properties of... more In this paper, we present theoretical investigations of the electronic and magnetic properties of the ordered ferromagnetic Ga0.75Mn0.25N and Al0.75Mn0.25N in zinc-blende structure using all electron full-potential (linear) augmented plane waves plus local orbitals calculations within the density functional theory and local spin-density approximation. The analyses of the band structures, density of states, total energy, exchange interactions and magnetic moments reveal that both the alloys may exhibit a half-metallic ferromagnetism character and the valence band is ferromagnetically coupled to the Mn atoms. The total magnetization of the cell is evaluated as 4.0 µB. (Some figures in this article are in colour only in the electronic version)
FT-IR, NMR and UV-Visible Spectral Investigations, Theoretical Calculations, Topological Analysis, Chemical Stablity and Molecular Docking Study on Novel Bioactive Compound: The 5-(5-Nitro Furan-2-Ylmethylen), 3-N-(2-Methoxy Phenyl),2-N’-(2-Methoxyphenyl) Imino Thiazolidin-4-One
SSRN Electronic Journal
h-BN nanosheets doped with transition metals for environmental remediation; a DFT approach and molecular docking analysis
Materials Science and Engineering: B
Cation effect on electronic, optical and thermoelectric properties of perovskite oxynitrides: Density functional theory
Materials Science in Semiconductor Processing
Abstract Perovskite oxynitride are of great interest due to their use as photo-catalysts. We inve... more Abstract Perovskite oxynitride are of great interest due to their use as photo-catalysts. We investigated the electronic, thermoelectric and optical properties of ATaO2N (A = Ba, Sr, Ra) with generalized gradient plus Hubbard approximation (GGA + U). In electronic properties, we have computed, for each compound, densities of states (total and partial), band structure to extract their band gaps, nature and transition probability when the cation changes. Optical properties were explored by calculating dielectric constant e (ω), refractive index n (ω), reflectivity R (ω), optical loss L (ω), and absorption coefficient I (ω) response against different photon energies. In order to examine the possibility of using these compounds in thermoelectric devices, we calculated their transport properties from Boltzman transport theory. We examined their thermal conductivity κ, electrical conductivity σ, seebeck coefficient S, power factor PF and dimensionless figure of merit ZT.
Toward development of high-performance perovskite solar cells based on CH3NH3GeI3 using computational approach
Solar Energy
Abstract We reported numerical simulations of device performances made of methylammonium germaniu... more Abstract We reported numerical simulations of device performances made of methylammonium germanium halide (CH3NH3GeI3)-based perovskite solar cells. The main goal here is to seek for an efficient method to improve the device efficiency of alternative lead-free perovskite based on germanium solar cells by using various organic and inorganic hole transport materials. For that aspiration, the effect of several parameters on the solar cell performance were investigated such as thicknesses of perovskite, HTM, defect density, hole mobility, and metal electrode work function on the charge collection. The device simulation revealed that the optimum thickness of CH3NH3GeI3 absorber is found around 600 nm. Furthermore, Ge-based perovskite solar cells with Cu2O and D-PBTTT-14 as HTM exhibited a remarkable overall power conversion efficiency reaching 21%. The defect density reduction is a critical factor to improve the solar cell performance and should be controlled under the order of ∼1015 cm3. Further simulations were performed to study the effect of operating temperature on the performance. Our simulation results advocate for a viable route to design hole-transporting materials for highly efficient and stable perovskite solar cells with low cost.
Enhanced thermoelectric properties of ASbO 3 due to decreased band gap through modified becke johnson potential scheme
Journal of Physics and Chemistry of Solids
Abstract Using density functional theory (DFT) calculations, we have explored the effect of Ag an... more Abstract Using density functional theory (DFT) calculations, we have explored the effect of Ag and Cs atoms on the electronic transport properties of ASbO 3 (A = K, Ag and Cs). We employed first principle calculations for investigation of electronic, optical and thermoelectric properties of ASbO 3 compounds. The exchange and correlation potential (E XC ) was treated by the modified Becke Johnson functional (mBJ). The optimized lattice constants and internal cell parameters were in agreement with the available experimental data. The self-consistence density of state and band-structure calculations show that Cs- d and Ag- d states remains in valence band and dominate below the Fermi level, while Sb- s/p states mainly contribute in conduction band. When Ag and Cs for K substitution take place, there is a gradual hybridization of Cs- d and Ag- d states results. Optical spectra show the main absorption peak in between 8.0 and 13.0 eV depends on the substituent nature and could be due to transition from hybridized band (Sb- d and Sb- s ), below E F to free Ag and Cs- s/p/d states. Frequency-dependent refractive index, n(ω), and the extinction coefficient, k(ω), of ASbO 3 were also calculated for the radiation upto 40 eV. We combined the outputs of DFT to transport theory based on Boltzmann equation to calculate the potential use of the ASbO 3 as thermoelectrics. The change of the alkaline element affected both of electrical conductivity, Seebeck coefficient and thermal conductivity.
Transport Phenomenon in Boron–GroupV Linear Atomic Chains Under Tensile Stress for Nanoscale Devices and Interconnects: First Principles Analysis
IEEE Transactions on Electron Devices, 2016
Density functional theory and nonequilibrium Green's function-based first principle calculati... more Density functional theory and nonequilibrium Green's function-based first principle calculations have been performed for an in-depth analysis of infinitely long boron-groupV (N, P, As, and Sb) linear atomic chains (LACs) under tensile stress. The analysis revealed the presence of dative bond among the atoms of LAC, and loses stability of the structures with applied stress. The boron phosphide (BP) LAC demonstrates superior withstanding capability against external tensile stress than the other LACs studied. Boron arsenide and boron antimonide (BSb) LACs are observed to offer remarkable electrical as well as thermal transport in comparison to boron nitride and BP counterparts. Out of the four LACs examined, BSb LAC is observed as the best contender for nanoscale interconnects, while BP LAC scrutinized to be a suitable candidate for channel material of nanoscale devices.
Magnetic and electronic properties of Neptunium chalcogenides from GGA+U+SOC and DFT investigations
Journal of Magnetism and Magnetic Materials, 2017
Abstract First-principles calculations techniques were employed to explore the structural, electr... more Abstract First-principles calculations techniques were employed to explore the structural, electronic and magnetic properties of Neptunium chalcogenides (Np 2 X 5 , X = S, Se and Te). No experimental or theoretical studies of their physical properties have been previously reported in the literature. The presence of highly localized f states has requested the employment of the spin orbit coupling and GGA + U approach in order to describe correctly the f–f coupling. Np 2 X 5 was found metallic with high magnetic character due to the Neptunium presence. Fermi surfaces of Np 2 Te 5 have shown a greater electrical conductivity compared to Np 2 Se 5 and Np 2 S 5 . The magnetic moment was found to be between 13.24 and 13.92 μ B , principally induced by Np f and d -orbitals as well as the spin-polarization of the chalcogenes (Te, Se, S) induced by Np. Neptunium chalcogenides have shown interesting magnetic properties and should be manipulated with precaution due to their radioactive properties.
Predicted Thermoelectric Properties of the Layered XBi4S7 (X = Mn, Fe) Based Materials: First Principles Calculations
Journal of Electronic Materials, 2016
We report a theoretical investigation of electronic structures, optical and thermoelectric proper... more We report a theoretical investigation of electronic structures, optical and thermoelectric properties of two ternary-layered chalcogenides, MnBi4S7 and FeBi4S7 , by combining the first principles density functional calculations and semi-local Boltzmann transport theory. The calculated electronic band structure have demonstrated that both compounds exhibit indirect band gaps. The optical transitions are explored via the dielectric function (real and imaginary parts) along with other related optical constants including refractive index, reflectivity, and energy loss spectrum. These chalcogenides have exhibited interesting thermoelectric properties such as Seebeck’s coefficient, electrical and thermal conductivity, and power factor as function of temperatures.
Ab Initio Calculation of Electronic Structure and Magnetic Properties of Rare Earth Nitride Using LDA+U Approach: EuN and GaEuN
Materials Science Forum - MATER SCI FORUM, 2009
A review on perovskite materials with solar cell prospective
International Journal of Energy Research
Revealing the optoelectronic properties of Re-based double perovskites using the Tran-Blaha modified Becke-Johnson with density functional theory
Journal of Molecular Modeling
Effect of Coulomb interactions on optoelectronic properties of Eu doped lanthanide stannates pyrochlore: DFT + U investigations
Journal of Solid State Chemistry
Exploring fundamental properties of Mg 0. 915 A 0 . 085 H 2 (A = Ti, Fe) for potential hydrogen storage application: First‐principles study
International Journal of Energy Research
ACS Omega
We reported a systematic study of the effects of Y doping BaTiO 3 at Ba and Ti sites. We assessed... more We reported a systematic study of the effects of Y doping BaTiO 3 at Ba and Ti sites. We assessed the structural, electronic, and optical properties by employing first-principles calculations within the Tran−Blaha-modified Becke−Johnson (TB−mBJ) potential and generalized gradient approximation + U approaches. We calculated the lattice constants and bond lengths for pure and Y-doped BaTiO 3. We explored the consequences of electronic structure and optical property modification because of Y doping in BaTiO 3. Indeed, Y doping has led to various modifications in the electronic structures of BaTiO 3 by inducing a shift of the conduction band through lower energies for the Ba site and higher energies for the Ti site. It was found that Y doping, either at Ba or at Ti sites, strongly enhanced the BaTiO 3 dielectric constant properties. The transformation in bonding was explored via the charge density contours and Born effective charges. We used the state of art of polarization theory based on finite difference and Berry-phase approaches to investigate piezoelectricity. Y doping has increased the dielectric constants but canceled the piezoelectricity as they changed to metallic nature. We could look into the future for potential doping, preserving the semiconductor nature of BaTiO 3 and increasing the permittivity with large dielectric loss.
Thiophene/Graphene Interface Peculiarities for Potential Organic Electronic Applications
Journal of Nanomaterials & Molecular Nanotechnology
Electronic and optical properties of functionalized zigzag ZnO nanotubes
Journal of molecular modeling, Jan 4, 2018
The present paper reports the analysis of surface decoration on the structural, electronic, and o... more The present paper reports the analysis of surface decoration on the structural, electronic, and optical properties of (n,0) ZnO nanotubes, performed by means of a density function theory based ab-initio approach. Fe functionalization induced buckling in ZnO nanotubes affects its electronic and optical properties. Increase in Fe functionalization leads to better stability of ZnO nanotube and shows enhanced metallic character. The possibility of its use in optoelectronics has been analyzed in terms of dielectric constant, absorption coefficient, and refractive index. In another observation, the high sensitivity of the HCN molecule for the Fe-incorporated ZnO nanotube suggests it as a potential gas sensor. Graphical abstract HCN-adsorbed Fe-ZnO nanotube, electron difference density, and PDOS analysis of different orbitals.
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Papers by Souraya Goumri-Said