Browsing by Author "Boudine, B."

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    Effect of copper doping on the photocatalytic activity of ZnO thin films prepared by solegel method
    (Elsevier, 2015) Saidani, T.; Zaabat, M.; Aida, M.S.; Boudine, B.
    In the present work, we prepared undoped and copper doped ZnO thin films by the sol egel dip coating method on glass substrates from zinc acetate dissolved in a solution of ethanol. The objective of our work is to study the effect of Cu doping with different concentrations on structural, morphological, optical properties and photocatalytic activity of ZnO thin films. For this purpose, we have used XRD to study the structural properties, and AFM to determine the morphology of the surface of the ZnO thin films. The optical properties and the photocatalytic degradation of the films were examined by UVevisibles spectrophotometer. The Tauc method was used to estimate the optical band gap. The XRD spectra indicated that the films have an hexagonal wurtzite structure, which gradually deteriorated with increasing Cu concentration. The results showed that the incorporation of Cu decreases the crystallite size. The AFM study showed that an increase of the concentration of Cu causes the decrease of the surface roughness, which passes from 20.2 for Un-doped ZnO to 12.16 nm for doped ZnO 5 wt% Cu. Optical measurements have shown that all the deposited films show good optical transmittance (77%e92%) in the visible region and increases the optical gap with increasing Cu concentration. The presence of copper from 1% to 5 wt% in the ZnO thin films is found to decelerate the photocatalytic process.
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    Electrodeposition And Characterization Of Zns Nanostructures For Solar Cells Application
    (Oum-El-Bouaghi University, 2018) Mentar, Loubna; Ghezali, K.; Boudine, B.; Azizi, A.
    In the last few years, metal oxides nanostructures have attracted quickly increasing attention, due to their very interesting properties .Among them, Zinc sulfide (ZnS) semiconductor is an appropriate candidate as window or buffer layer in solar cells applications. ZnS thin films were prepared at room temperature by electrochemical deposition using zinc sulfate and sodium thiosulfate solution at pH 2.7. In this paper, we investigated the influence of the concentration of zinc sulfate on structural, morphological and optical properties for ZnS thin films electrodeposits. SEM images demonstrated that the morphology of ZnS thin films depend greatly on the intial concentration of ZnSO4. XRD studies confirmed the presence of zinc blende structure. The optical measurements (UV-Vis) show a large band gap between 3.4 –3.9 eV depending on the concentration of zinc sulfate.
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    Fabrication, structural and optical characterization of In doped ZnO thin films prepared by the colloidal method
    (Oum-El-Bouaghi University, 2014) Medjaldi, M.; Touil, O.; Zaabat, M.; Boudine, B.; Halimi, O.; Sebais, M.
    Regarding to the excellent conductivity and high transparency in the visible range, the zinc oxide (ZnO) films have been widely used as transparent electrodes in optoelectronic devices, ZnO is a direct wide band-gap (3.37 eV) semiconductor. The conductivity of ZnO will be largely enhanced by doping little In, but it still keeps high transparency. So, IZO film has been widely investigated and is considered to be a promising possible alternative to ITO films. This work consist to the fabrication and characterization of ZnO:In thin films. The sample preparation was carried out by the colloidal method. The pure and In doped ZnO thin films were deposited using a dip-coating technique on glass matrix. The optimal condition for samples fabrication has been investigated. The XRD and Raman characterizations show that the ZnO thin film crystallize with a wurtzite structure. The optical properties of ZnO thin films doped In reveal that doping changes the optical gap of ZnO.
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    Modification Of The Thermally Exfoliated Vermiculite By Sonication And Grafting Methods
    (Oum-El-Bouaghi University, 2016) Terchi, S.; Bougherara, H.; Hamrit, S.; Boudine, B.; Kebabi, B.
    n the present study, the thermally exfoliated vermiculite has been sonicated in order to grafting with the butyl-imidazolium. A suspension of vermiculite-water with 1% of concentration was sonicated at 20 KHz. This led to the decrease in the size of grains to16 µm after 2 h of treatment. Increasing of sonication time, presence of H2O2 , and the increase of the vermiculite concentration have caused an accentuation of sonication effect, this resulted the decreasing of the size to 10 µm. Moreover, a 2% fraction of submicron-sized particles was appeared. The pH of the vermiculite suspensions was increased. The number of the -OH sites was determined by acid-base titration using Gran method. The infrared spectra of the raw and sonicated vermiculites in H2O or containing H2O2 were very similar. In the presence of H2O2 , two bands were observed at 1380 and 1460 cm-1 . These are due to the presence of carbonates anions formed during sonication in H2O2 . XRD spectra showed that the sonication did not affect the vermiculite structure. The grafting was carried out on sonicated samples during 5 h in H2O. This was realized in two steps. In the first step, we grafted 3-chloropropyltrimethoxysilane instead of the –OH sites. In the second step, we conducted a nucleophilic substitution of chlorine with methyl-imidazole. We proved by infrared spectroscopy and Gran method that grafting was real and XRD that this was not an intercalation
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    Structural And Optical Properties Of Cdse Doped Kcl Single Crystal
    (Oum-El-Bouaghi University, 2012) Bouhdjer, L.; Addala, S.; Chala, A.b.; Halimi, O.; Boudine, B.; Sebais, M.; Kara, S.
    Undoped and doped KCl single crystals by CdSe nanocrystals (NCs) have been grown by Czochralski (CZ) method with pulling rates in the 8-10 mm/h range. The crystals thus obtained were cleaved into samples of required size. The structural investigation of these samples has been deduced from Ө-2Ө (XRD) and Raman spectroscopy. The nano-size of CdSe aggregates in KCl host determined from XRD measurements by using the Sheerer formula. The Raman spectroscopy presented the LO mode vibration relative of (Cd-Se) chemical liaison. Moreover, the results of the optical absorption and photoluminescence spectra confirmed the nano-size of CdSe aggregates were observed band absorption located at 622,5nm relative of electronic transition 1se-1s3/2 of CdSe, with a blue shift from the bulk gap of ΔEg=0,26eV (Eg (CdSe) bulk=1,73eV), while the photoluminescence showed a band situated at 643, 55 nm, with displacement Eg towards the short wavelength (blue shift), this bleu shift due to the nanometric size of CdSe aggregates.