Browsing by Author "Bin Omran, S."

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Computational Investigations on Band Structure and Optical Properties of the Besexte1-X Alloys Through the Fp-Lapw Approach
(Elsevier Gmbh, 2017) Hadji, K.; Abdiche, A.; Soyalp, F.; Bin Omran, S.; Khenata, R.
In this paper, we have theoretically explored the structural, electronic and optical properties of the zinc blende structure of ternary alloys using the full-potential linearized augmented plane wave (FP-LAPW) method within the density-functional theory (OFF) as implemented in the Wien2 K code. The electronic properties were computed using the following two approximations: the generalized gradient approximation (GGA) and the Tran-Blaha-modified Becke-Johnson potential (TB-mBJ). The obtained results clearly show that ternary alloys exhibit large and direct band gaps while binary compounds are indirect band gap semiconductors. (C) 2016 Elsevier GmbH. All rights reserved.
Optoelectronic and Thermoelectric Properties of Zintl Yli3a2 (A = Sb, Bi) Compounds Through Modified Becke-Johnson Potential
(Iop Publishing Ltd, 2016) Seddik, T.; Ugur, G.; Khenata, R.; Ugur, S.; Soyalp, F.; Murtaza, G.; Bin Omran, S.
In the present work, we investigate the structural, optoelectronic and thermoelectric properties of the YLi3X2 (X = Sb, Bi) compounds using the full potential augmented plane wave plus local orbital (FP-APW + lo) method. The exchange-correlation potential is treated with the generalized gradient approximation/local density approximation (GGA/LDA) and with the modified Becke-Johnson potential (TB-mBJ) in order to improve the electronic band structure calculations. In addition, the estimated ground state properties such as the lattice constants, external parameters, and bulk moduli agree well with the available experimental data. Our band structure calculations with GGA and LDA predict that both compounds have semimetallic behaviors. However, the band structure calculations with the GGA/TB-mBJ approximation indicate that the ground state of the YLi3Sb2 compound is semiconducting and has an estimated indirect band gap (Gamma-L) of about 0.036 eV while the ground state of YLi3Bi2 compound is semimetallic. Conversely the LDA/TB-mBJ calculations indicate that both compounds exhibit semiconducting characters and have an indirect band gap (Gamma-L) of about 0.15 eV and 0.081 eV for YLi3Sb and YLi3Bi2 respectively. Additionally, the optical properties reveal strong responses of the herein materials in the energy range between the IR and extreme UV regions. Thermoelectric properties such as thermal conductivity, electrical conductivity, Seebeck coefficient, and thermo power factors are also calculated.
Structural, Elastic, Electronic and Optical Properties of Cu3tmse4 (Tm = V, Nb and Ta) Sulvanite Compounds Via First-Principles Calculations
(Amer Scientific Publishers, 2013) Bougherara, K.; Litimein, F.; Khenata, R.; Ucgun, E.; Ocak, H. Y.; Ugur, S.; Bin Omran, S.
The structural and optoelectronic properties of the cubic Cu3TMSe4 (TM = V, Nb and Ta) sulvanite compounds have been calculated using a full-potential augmented plane wave plus local orbitals (FP-APW + lo) method within the density functional theory. The exchange-correlation potential was treated with the generalized gradient approximation of Wu and Cohen (WC-GGA) to calculate the total energy. Moreover, the Engel-Vosko generalized gradient approximation (EV-GGA) and the modified Becke-Johnson potential (TB-mBJ) were also applied for the electronic and optical properties. The ground state properties, including, lattice constants, bulk modulus are in reasonable agreement with the available experimental and theoretical data. The elastic constants C-ij are computed using the total energy variation versus strain technique. The polycrystalline elastic moduli, namely; shear modulus, Young's modulus, Poisson's ratio and anisotropic factor were derived from the obtained single-crystal elastic constants. As a result, brittleness behaviour of these compounds is interpreted via the calculated elastic constants C-ij. The calculations of the electronic band structure show that these compounds have an indirect energy band gap (R-X) and the TB-mBJ approximation yields larger fundamental band gaps compared to those of WC-GGA and EV-GGA. The dielectric function, refractive index, extinction coefficient, reflectivity, and energy loss function were calculated for radiation up to 45 eV.