Browsing by Author "Nadir Bouarissa"

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    Gallium Antimonide Spherical Semiconductor Quantum Dots
    (université msila, 2022) Lynda Lakha; Fadila Mezrag; Nadir Bouarissa
    The quantum effects at the nano-metric level have been observed in a variety of confined structures, particularly in semiconductor quantum dots. In this contribution, the electronic and optical properties of GaSb spherical semiconductor quantum dots are investigated. For the calculations, the pseudo potential approach was employed. The size dependence of the energy gaps at Г, X and L points, the effective masses of electrons and heavy-holes, the refractive index, and the dielectric function for a studied GaSb spherical quantum dot are analyzed and discussed. When the degree of quantum confinement effect was changed by decreasing the radius of the spherical quantum dots, a striking charge in comparison to the bulk values has been obtained. Our results indicate that as the quantum dot radius is raised, most of properties rapidly decrease. This demonstrates an improvement in the mobility of the material. However, the refractive index and the dielectric constant are increased with increasing the radius of the nano-crystal. © 2022 The Electrochemical Society (“ECS”). Published on behalf of ECS by IOP Publishing Limited. [DOI: 10.1149/2162-8777/ ac942e]
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    Halide double perovskite Cs2AgInBr6 for photovoltaic’s applications: Optical properties and stability
    (Université de M'sila, 2022) Adel Menedjhi; Nadir Bouarissa; Salima Saib; Khaled Bouamama
    Theoretical calculations on halide double perovskite Cs2AgInBr6 electronic properties and optical spectra are carried out. The hybrid functional B3LYP calculations have been used indicating a 1.427 eV direct to band gap. The optical absorption coefficient has been determined showing a high-absorption (> 104 cm−1) within a large absorption range suggesting that the perovskite of interest-based solar cells may reach a good solar efficiency. Based on the refractive index spectrum, the Cs2AgInBr6 static refractive index is estimated and found to be 2.09. The stability, phonon spectrum, electron effective mass and absorption spectrum with solar spectrum at AM1.5 of Cs2AgInBr6 have been computed and verified
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    Quantum and conversion efficiencies optimization of superstrate CIGS thin-films solar cells using In2Se3 buffer layer
    (Université de M'sila, 2020) Idris Bouchama; Samah Boudour; Nadir Bouarissa; Zahir Rouabah
    In this present contribution, AMPS-1D device simulator is employed to study the performances of superstrate SLG/TCO/p-Cu(In,Ga)Se2(CIGS)/n-ODC/n-In2Se3/Metal thin film solar cells. The impact of the TCO and Metal work functions on the cell performance has been investigated. The combination of optical transparency and electrical property for TCO front contact layer is found to yield high efficiency. The obtained results show that the TCO work function should be large enough to achieve high conversion efficiency for superstrate CIGS solar cell. Nevertheless, it is desirable for Metal back contact layer to have low work function to prevent the effect of band bending in the n-In2Se3/Metal interface. Several TCOs materials and metals have been tested respectively as a front and back contact layers for superstrate CIGS solar cells. An efficiency of 20.18%, with Voc z 0.71 V, Jsc z 35.36 mA/cm2 and FF z 80.42%, has been achieved with ZnSn2O3-based as TCO front contact layer. In the case of SnO2:F front contact and indium back contact layers, an efficiency of 16.31%, with Voc z 0.64 V, Jsc z 31.4 mA/cm2 and FF z 79.4%, has been obtained. The present results of simulation suggest an improvement of superstrate CIGS solar cells efficiency for feasible fabrication.