Browsing by Author "Ghemid, S."

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    First-principle study of structural and optical properties of MgSiSb2
    (University of Eloued جامعة الوادي, 2018-02-05) Benlamari, S.; Meradji, H.; Ghemid, S.
    In this work, we report the results of structural and optical properties of the ternary II-IV-V2 (MgSiSb2) chalcopyrite semiconductor using the full-potential linearized augmented plane wave (FP-LAPW) scheme in the frame of generalized gradient approximation (GGA). The lattice parameters (a, c), the internal structure parameter, u, describing the position of Mg atom and the (c/a) ratio are optimized. The results are in good agreement with theoretical data obtained by using other methods. The linear optical properties namely the real and imaginary parts of dielectric function, refractive index and extinction coefficient are calculated. MgSiSb2 compound is observed to present very weak birefringence.
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    PHASE STABILITY, ELECTRONIC AND OPTICAL BEHAVIOR OF PbS, PbSe AND PbTe COMPOUNDS
    (University of Eloued جامعة الوادي, 2018-02-05) Megdoud, Y.; Mahdjoubi, R.; Tairi, L.; Bendjedou, H.; Ghemid, S.; Meradji, H.
    Ab initio calculations based on density functional theory using the full potential linearized augmented plane wave method (FP-LAPW) have been carried out to find the structural stability of different crystallographic phases, the electronic and optical properties of PbS, PbSe and PbTe compounds. The zinc blende (B3), rock salt (B1) and CsCl (B2). crystal structures are considered and the exchange and correlation potential is treated by the generalized-gradient approximation using the Perdew– Burke–Ernzerhof parameterization. Moreover, the modified Becke-Johnson (mBJ) scheme is also applied to optimize the corresponding potential for the band structure calculations. Results show that the rock salt phase is the stable structure in the ground state adopted by PbS, PbTe and PbSe compounds. Moreover, the band structure calculations reveal a semiconductor behavior for all the compounds. The dielectric function, reflectivity, Refractive index and absorption coefficient are calculated to investigate the optical properties.