Browsing by Author "Guerbous, L."

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    Properties of SiC-Based Luminescent Composite Thin Film As Light-Harvesting Material
    (Springer, 2020) Benfadel, K.; Kaci, S.; Talbi, L.; Keffous, A.; Benmounah, A.; Bozetine, I.; Boukezzata, A.; Rahmoune, R.; Ouadah, Y.; Guerbous, L.; Kermad, A.; Achacha, S.; Mahmoudi, B.; Cheraga, H.
    In this study, we present the use of SiC/PVA composite thin films as downshifting layers (LDS) in order to improve the photoelectrical parameters of a Si-based solar cell. We showed that the adding of these layers increases the short circuit current density. This increase could surely lead to the improvement of the power conversion efficiency since the two parameters are relied. The J–V characterizations of the as made c-Si solar cell measured under white light showed an enhancement of the photocurrent after coating the c-Si solar cell with SiC-based LDSs. The same behavior was noticed upon exposure to UV light illumination which depended strongly on the elaboration conditions of the luminescent porous SiC particles. A decrease in total reflectance of the c-Si solar cell coated with SiC based LDS was also observed. Spectral Response measurements have shown significant enhancement where the solar cells have poor optical response.
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    γ-radiation, chemical synthesis of Ce3+ : Gd2Si2O7/SiO2 nanocomposite
    (Elsevier, 2021) Ladjouzi, S.; Guerbous, L.; Bensuici, F.; Bendiba, G.
    In this work, Ce3+:Gd2Si2O7/SiO2(0.1 mol% Ce3+) nanocomposite powders were successfully synthesized via γ-irradiation, followed by thermal treatment at 900 °C for 2h.The radiations were carried out in a 60Co γ-source chamber at a dose up to 50 kGy. The structural, morphological and optical properties were investigated using X-ray diffraction analysis (XRD), Raman spectroscopy, Transmission electron microscopy (TEM) and Photoluminescence (PL) spectroscopy. XRD analysis reveals the formation of pure orthorhombic δ-Gd2Si2O7 Gadolinium pyrosilicate (δ-GPS)crystalline phase. The average particles size ranges from 30 to 50 nm when the γ-doses increase up to 50 kGy. Raman scattering shows that the intensity of Raman bands significantly increases with increasing of γ-doses. TEM observations show well dispersed spherical GPS nanoparticles within the silica glass host and confirmed the particles size and size distribution dependence on the γ-irradiation dose. Finally, photoluminescence measurements show that the emission intensity corresponding to 5d-4f transition of Ce3+increases with increasing of γ-irradiation dose due to high purity, better crystallinity and uniform distribution of Ce3+ions into GPS nanostructures
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    γ-Ray irradiation effect on GdBO3/silica:Ce3+ composite prepared by sol gel method
    (Elsevier, 2015) Ladjouzi, S.; Tala-Ighil, Razika; Iratni, A.; Izerrouken, M.; Guerbous, L.; Hadji, S.; Bensouici, F.; Pérez, F.J.
    Samples of GdBO3 doped with Ce3+ embedded in amorphous silica matrix were obtained by sol gel process and heat-treat at 1000°C for 2h in argon atmosphere. After elaboration, the samples were irradiated with γ-rays using cobalt (60Co) source in the dose range from 1 to 5kGy. The irradiation effect of γ-rays on structural and optical properties of the synthesized samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transforms infrared spectroscopy (FTIR) and photoluminescence spectroscopy. XRD and TEM-EDS results reveal that γ-ray irradiation reduces the crystallite size from 55nm to 30nm. It is found from FTIR study that the absorption bands intensity assigned to structural groups containing BO4 and BO3 units as well as the banding of Si-O-Si bond increases with γ-ray dose up to 4kGy. While photoluminescence measurements show that the emission bands attributed to the 5d→4F transition of Ce+3 ion intensity decreases, it is still significant even after irradiation to a dose of 5kGy. From this results it is concluded that the γ-ray irradiation up to a dose of 5kGy improve the structural and morphological quality of the synthesized GdBO3/silica: Ce3+ without altering significantly its luminescence properties.