Browsing by Author "Attaf, N."

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    Copper Oxide Thin Films Deposition By Spray Pyrolysis
    (Oum-El-Bouaghi University, 2014) Lamri Zeggar, M.; Aida, M. S.; Attaf, N.
    CuO thin films have been growth on to heated glass substrates by varying substrate temperatures from 280 to 400°C. The effect of the pyrolysis on structural, optical and electrical proprieties of CuO films has been investigated in the present work. Phase analysis was carried out using Micro-Raman scattering. The optical properties were studied by mean of UV–visible and near infrared spectroscopy. The conductivity was measured by the electrical D.C transport. The structural analysis indicates the presence of a single CuO phase with a monoclinic structure. The optical transmittance spectra show a high absorption of all films in the visible region. The electrical characterization indicates a maximal electrical conductivity of 1,03 × 10-6 (Ω .cm)-1.
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    Investigation on chemical bath deposited CdS thin films
    (Oum-El-Bouaghi University, 2011) Moualkia, H.; Attaf, N.; Hadjeris, L.; Herissi, L.; Abdelmalek, N.
    n this work we report the structural, optical and electrical properties of CdS thin films prepared by chemical bath deposition (CBD) under the effect of solution temperatures. The XRD patterns show that the films have a hexagonal phase with a preferential (002) orientation. The structural parameters such as the grain size, dislocation density and strain are calculated for the films. The transmission spectra, recorded in the UV visible range reveal a high transmission coefficient (85%) in the obtained films. The optical gap values of 2-2, 4 eV are deduced from the UV-visible transmittance. The electrical characterizations show that the films deposited possess good optoelectronic properties.
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    Preparation and characterization of CdS thin films
    (IEEE, 2012) Moualkia, H.; Attaf, N.; Hadjeris, L.; Herissi, L.; Abdelmalek, N.
    In this work we report the structural, optical and electrical properties of CdS thin films prepared by chemical bath deposition (CBD) under the effect of solution temperatures. The solution temperatures used vary between 55 and 75 °C. The XRD patterns show that the films have a hexagonal phase with a preferential (002) orientation. The structural parameters such as the grain size, dislocation density and strain are calculated. The transmission spectra, recorded in the UV visible range, reveal a high transmission coefficient (85%) of the prepared films and an optical band gap values of 2 - 2.4 eV. The electrical measurements show that the dark conductivity values increase from 10-7 to 10-4 (Ω.cm)-1 at higher temperature (Ts > 65°C). It is found that the photoconductivity of the deposited films is two to five decades larger than the dark conductivity, and the photoconductivity to the dark conductivity ratio obtained at 3000 Lx vary from 102 to 105. From these results we inferred that the elaborated CdS thin films exhibit good properties intended for solar cell window layers.
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    Realization and study of ZnO thin films intended for optoelectronic applications
    (Oum-El-Bouaghi University, 2011) Herissi, L.; Hadjeris, L.; Moualkia, H.; Abdelmalek, N.; Hafdallah, A.; Attaf, N.; Aida, M. S.
    The objective of this study is the realization of zinc oxide (ZnO) thin films intended for optoelectronic applications. For this purpose, thin films were prepared by spray pyrolysis technique from zinc acetate solutions of different molarities (0.025 M, 0.05 M and 0.1 M) used as precursors on Si and glass substrates heated between 200 and 500 °C. The nozzle to substrate distance was varied between 20 and 30 cm. Structural, optical and electrical properties of the films have been studied. The results indicated that the films deposited were transparent in the visible region, well adherent to the substrates and presented surface roughness. All samples were polycrystalline in nature, having hexagonal würtzite type crystal structure. A (002) preferred orientation was observed at 450°C and a 0.025M molarity. The optical energy gap measured was about 3.3 eV. The refractive index values presented small variations with the deposition conditions and were located between 1.8 and 2.0. The electrical properties showed that the samples are natively n‑type semiconductor and the electrical conductivity at room temperature varied between 10-5 and 102 (Ω.cm)‑1.
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    Substrate effect temperature on Cu2ZnSnS4 thin films deposited by ultrasonic technique
    (Oum-El-Bouaghi University, 2011) Daranfed, W.; Fassi, R.; Hafdallah, A.; Ynineb, F.; Attaf, N.; .Aida, M.S; Hadjeris, L.; Rinnert, H.; Bougdira, J.
    Cu2ZnSnS4 (CZTS) thin films are a potential candidate for absorber layer in thin film solar cells. CZTS films were deposited by spray ultrasonic technique. An aqueous solution composed of copper chloride, zinc acetate, tin chloride and thiourea like precursors is sprayed on heated glass substrates at various temperatures. The substrate temperature was changed from 280°C to 360°C in order to investigate its influence on CZTS films properties. The DRX analyses indicated that Cu2ZnSnS4 films have nanocrystalline structure with (112) preferential orientation and a crystalline size, ranged from 30 to 50 nm with increasing substrate temperature. The obtained films are composed of SnS, ZnO, ZnS and Cu2ZnSnS4 phases. The optical films characterization was carried by the measurement of UV-visible transmission. The optical gap was deduced from the absorption spectra. Broad emissions at around 1.27 eV was observed in the photoluminescence spectrum measured at 77 K.