Browsing by Author "Nouiri, Abdelkader"

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    Nd
    (Oum-El-Bouaghi University, 2013) Baziz, Leila; Nouiri, Abdelkader
    In this work, we used a nanosecond Nd: Yag laser (l=532 nm) with a pulse duration of 15 ns, and an energy of 50 mJ and, therefore, we studied the threshold ablation of industrial aluminum alloy. The composition of the recuperated aluminum (% mass) is (72.02 Al, Si 13.05, 6.34 Zn, 4.28 O, 2.08 Mg, 1.75 Cu, 0.48 Ni) and the industrial aluminum is (83.10 Al, 1.66 Si, 4.12 Fe 2.17 O, 1.20 Mg, 5.47 Cu, 1.74 Mn, 1.79 Pb). For nanosecond lasers, the primary energy is lost by thermal diffusion in the irradiated target, because there is enough time to convert optical energy into thermal energy and heat spread. Fusion and / or evaporation may take place if the surface temperature exceeds the critical point when the energy of radiation is above the ablation threshold. The results shows that the threshold ablation of the recuperated aluminum is lower than that of the aluminum industry, it is about 5 J.cm-2 for the recovered aluminum and 10 J.cm-2 for the industrial aluminum. The threshold ablation is shifted towards the low values when the number of pulses increases.
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    Simulation Study Of Ingan/gan Multiple Quantum Well Solar Cells
    (Oum-El-Bouaghi University, 2014) Sayad, Yassine; Nouiri, Abdelkader
    It’s known that indium gallium nitride InGaN alloys has a direct band gap varying from 0.7 to 3.4 eV which covers nearly the whole solar spectrum making it material of choice to make tandem solar cells. In other hand, it’s experimentally known that uses of InGaN/GaN multiple quantum well MQW structures in GaN based devices decreases surface recombination and, thus, enhances devices performance. Here, we present a simulation study of multiple quantum well MQW InGaN/GaN solar cells, where cell's active region is formed by a number of InGaN quantum wells (QWs) separated byGaN quantum barriers (QBs). We will present indium element content of InxGa1-xN wells and number of InGaN/GaN periods impacts on solar cell parameter