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Item Effect Of Solvents On The Properties Of Zno Thin Layers Obtained By Sol Gel Dip Coating Process(Oum-El-Bouaghi University, 2014) Boukaous, Chahra; Telia, Azzedine; Horwat, David; Ghanem, Salah; Miska, PatriceUndoped Zinc Oxide (ZnO) thin films have been grown on glass substrates by sol gel process associated with dip coating using two different solvents, ethanol and 2-methoxyethanol. The effects of these solvents on structural and optical properties of ZnO thin films have been studied. Crystallinity and surface morphology of the ZnO films were analyzed using X-ray diffractometry (XRD), Raman microscopy and atomic force microscopy (AFM). The optical properties were determined by means of photoluminescence spectroscopy (PL) and Fourier transform infrared spectroscopy (FTIR). The experimental results revealed a better crystalline quality and ultraviolet emission performance and a higher surface roughness for ZnO thin films prepared with 2-methoxyethanol.Item Two-dimensional Modelling And Simulation Of Cigs Thin-film Solar Cell(Oum-El-Bouaghi University, 2014) Tobbeche, S.; Amar, H.2 D Silvaco Atlas software is used for the study of a CIGS thin film solar cell in the configuration: ZnO(200 nm)/n-type CdS(50 nm)/ p-type CIGS(350 nm)/Mo. The cell performance is evaluated by implementing the defects created at the grain boundaries of the polycrystalline CdS and CIGS material and at the interface CdS/CIGS.The J-V characteristics and the external quantum efficiency EQE are simulated under AM 1.5 illumination. The conversion efficiency h of 20.35% is reached and the other characteristic parameters are simulated: the short circuit current density Jsc equals 35.62 mA/cm2, the open circuit voltage Voc is of 0.69 Vand the fill factor FF is of 82.7 %. The calculated external parameters of the solar cell are in good agreement with the measured characteristics. The simulation results also showed that the rise of the CdS thickness decreases all output parameters and the external quantum efficiencywhile the rise of the CIGS thickness improves all photovoltaic parameters and the external quantum efficiency. The highest efficiency of 21.08 % is reached for the CIGS thickness of 5 μm.Item 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.Item Channel Drop Filter Based On Coupled Cavity In Photonic Crystals(Oum-El-Bouaghi University, 2014) Bendjelloul, Rahima; Bouchematand, Touraya; Bouchemat, MohamedIn this paper, a five channel drop filter has been designed in a two dimensional photonic crystal with high dielectric rods in air. Each channel consists of a photonic crystal coupled cavity waveguide with double cavities combined with a line defect waveguide. Desired wavelengths are selected by setting different radii of the two point defects in the photonic crystal coupled cavity waveguides. Defect rods placed at the same channel have an identical radius. The performance of the designed filter has been numerically calculated using the finite difference time domain method. In the designed structure, higher efficiencies in all channels have been achieved.Item 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.Item Effect Of A Buffer Layer On The Performance Of Thin-film Cu(in,ga)se2 Solar Cells(Oum-El-Bouaghi University, 2014) Mostefaoui, M.; Mazari, H.; Khelifi, S.; Dabou, R.opper indium gallium diselenide (CuIn1-xGaxSe2 or CIGSe) solar cells has been considered to be one of the most promising thin-film solar cells and is important for terrestrial applications because of their high efficiency, long-term stable performance and potential for low-cost production. In this work, the CIGS heterojunction solar cell has been numerically simulated using SCAPS-1D tool. We study the influence of a buffer layer on the performance of the CIGSe solar cells. Quantum efficiency, Jsc ,Voc and efficiency has been calculated in different buffer layer materials (CdS, ZnS, ZnSe, InS).The solar cell optimized shows an efficiency of > 18% under the AM1.5G spectrum and one sun.Item Numerical Simulation Of Radiation Damage On The Device Performance Of Gaas Mesfets(Oum-El-Bouaghi University, 2014) Beddiafi, Y.; Saadoune, A.; Dehimi, L.In this work, the effect of the radiation on the current-voltage characteristics of device GaAs metal Schottky field effect transistors (MESFET) at room temperature is investigated. Numerical Simulation tuned by means of a physics based device simulator. When the substrate of this transistor is subjected to radiations, structural defects, which are created, have undesirable effects and can degrade the performance of the transistors. These defects appear like deep traps. Results showed that in the presence of donor traps the current-voltage characteristics increases. However, acceptor traps have a significant effect on the current-voltage characteristics. In the presence of acceptor traps, the space charge zone in the channel increases, hence, reduces the current drainItem Effect Of Al Doping On The Properties Of Electrodeposited Zno Nanostructures(Oum-El-Bouaghi University, 2014) Baka, Ouidad; Khelladi, Mohamed Redha; Azizi, AmorIn this study, Al-doped zinc oxide (AZO) nanostructures are prepared on polycrystalline fluorine-doped tin oxide (FTO)-coated conducting glass substrates from nitrates baths by the electrodeposition process at 70 °C. The electrochemical, morphological, structural and optical properties of the AZO nanostructures were investigated in terms of different Al concentration in the starting solution. It was found from the Mott–Schottky (M-S) plot that the carrier density of AZO nanostructures varied between 3.11´1020 to 5.56´1020 cm-3 when the Al concentration was between 0 and 5 mM. Atomic force microscopie (FM) images reveal that the concentration of Al has a very significant influence on the surface morphology and roughness of AZO thin films. X-ray diffraction (XRD) patterns demonstrate preferential (002) crystallographic orientation having c-axis perpendicular to the surface of the substrate and average crystallites size of the films was about 23–36 nm. As compared to pure ZnO, Al-doped ZnO exhibited lower crystallinity and there is a shift in the (002) diffraction peak to higher angles. ZnO nanostructures were found to be highly transparent and had an average transmittance of 80 % in the visible range of the spectrum. After the incorporation of Al content into ZnO the average transmittance increased and the band-gap tuning was also achieved (from 3.22 to 3.47 eV).Item Morphological And Optical Properties Of Sol-gel Derived Ni Doped Zno Thin Film(Oum-El-Bouaghi University, 2014) Saidani, T.; Zaabat, M.; Benaboud, A.; Boudine, A.In this work, we are interested in thin films of zinc oxide doped with nickel (Ni), deposited on glass substrates and elaborated by the sol-gel dip coating technique. The effects of the doping concentration in the range of outlet (1%, 3% and 5at%) have been thoroughly studied. The morphological properties of ZnO-Ni films were studied by Atomic Force Microscopy (AFM). The optical properties of the ZnO:Ni thin films were examined by UV-visible spectroscopy and the Tauc method was used to estimate the optical band gap and hall effect for electrical characteristique. Atomic Force Microscopy has indicated that the surface of the ZnO:Ni thin films have uniform and dense ZnO grains. The optical transmittance of ZnO:Ni thin films increased from 86 to about 93% from pure ZnO films to ZnO film doped with 3 wt% Ni and then decreased for 5 wt% Ni, and the optical band gap from 3.297 eV to 3.23eV. The electrical characterization performed using the technique of hall effect, gave a maximum electrical conductivity of 9.3 10-3(Ω.Cm)-1 obtained for the film doped with 3%Ni.Item The Study Of The Miniaturisation Effect On The Characteristics Of Patch Antenna Using The Wcip Method(Oum-El-Bouaghi University, 2014) Ziar, Toufik; Mellal, Saida; Farh, Hichem; Zaabat, Mourad; Azizi, CherifaThe demand of miniature electronic systems has been increasing for several decades. The physical size of systems is reduced due to advancements in integrated circuits. With reduction in size of electronic systems, there is also an increasing demand of small and low cost antennas. Patch antennas are one of the most attractive antennas for integrated RF systems due to their compatibility with microwave integrated circuits. In this paper, the effects of substrate dielectric constant and particularly the miniaturization of the antenna size on the return loss characteristics of patch micro strip antenna (MSPA) have been investigated using the wave concept iterative procedure (WCIP) method. Accuracy of the present results is compared with previous work which has been done theoretically and experimentally.Item Structural And Magnetic Properties Of Electrodeposited Nife Alloy On Silicon Nanowires.(Oum-El-Bouaghi University, 2014) Lamrani, S .; Guittoum, A.; Hadjersi, T.; Bouanik, S.; Mebarki, M.; Benbrahim, N.Perpendicular Silicon nanowires (SiNWs), having 20 micrometer in length, were fabricated by metal assisted chemical etching of n-type Si(100) wafers in aqueous HF-solution. In a second step, NiFe films were electrodeposited onto theses SiNWs. The structure and magnetic properties of as deposited NiFe layers were studied by X ray diffraction (XRD) and vibrating sample magnetometer (VSM). From X-ray diffraction, the FCC NiFe structure was evidenced with a lattice constant, a, equal to 3.5270 Å. From hysteresis curves, we compute the coercive field, Hc, values. We found that the Hc // values range from 102 Oe to 236 Oe.Item Temperature effect on the vibration characteristics of carbon nanotubes(Oum-El-Bouaghi University, 2014) Kheroubi, B.; Heireche, H.; Benzair, A.In this work, the thermal buckling properties of carbon nanotube with small scale effect are studied. Based on the nonlocal continuum theory and the Timoshenko beam model, the governing equation is derived and the critical buckling temperature is presented. The influences of the scale coefficients, the ratio of the length to the diameter, the transverse shear deformation and rotary inertia are discussed. It can be observed that the small scale effects are significant and should be considered for thermal analysis of carbon nanotube. The critical buckling temperature becomes higher with the ratio of length to the diameter increasing. Furthermore, for smaller ratios of the length to the diameter and higher mode numbers, the transverse shear deformation and rotary inertia have remarkable influences on the thermal buckling behaviors.Item The Effect Of Bath Temperature On The Electrodeposition Of Zinc Oxide Nanostructures Via Nitrates Solution(Oum-El-Bouaghi University, 2014) Mentar, Loubna; Lahmar, Hala; Mohamed Redha, Khelladia; Amor, AziziZinc oxide (ZnO) nanostructures were electrodeposited onto ITO coated glass substrates from nitrate medium at different temperatures. The electrochemical deposition process was analyzed and the characteristics of the nanostructures were discussed. The electrochemical results showed that the deposition temperature had an important effect on the current density and the film morphology. From the Mott-Schottky measurements, the flat-band potential and the donor density for the ZnO nanostructure are determined. The morphological, structural and optical properties were studied by scanning electron microscopy (SEM), x-ray diffraction techniques (XRD) and spectrophotometer in the ultraviolet UV–visible region. SEM images demonstrated that the morphology of ZnO nanostructures depend greatly on the bath temperature. The XRD patterns revealed the formation of phase-pure ZnO nanostructure with hexagonal wurtzite phase. The optical transmittance spectrum gave a high transmittance of 82 % at low temperatures, and the optical band-gap (Eg) of the ZnO nanostructures was between 3.25~3.49 eV.Item Synthesis, Characterization And Cytotoxic Effect Of Zno Nanoparticles Obtained By Mechanical Alloying(Oum-El-Bouaghi University, 2014) Benchelia, S.; Benosmane, D.; Mekki, E.; Tabet, N.ZnO nanoparticles with different grain sizes have been obtained by mechanical milling, after different treatment times: 3, 6, 12 and 24 hours. The final products have been characterized by different analytical techniques, such as X Ray Diffraction, Photoluminescence, Fourier transform infrared (FTIR) and UV-Visible spectroscopies. The cytotoxic effect of one selected concentration ZnO nanoparticles have been evaluated for paramecium growth kinetics and the mortality rate have been recorded as a function of time. Findings demonstrated that the evolution of the paramecium cell number is clearly affected by ZnO Nps presence.Item Electrical Characteristics Of Organic Light Emitting Diode “oled” Finite Difference Modeling(Oum-El-Bouaghi University, 2014) Benatia, Khaoula; Telia, AzzedineIn this paper, a finite difference modeling of single layer organic light emitting diode “OLED” based on MEH-PPV [Poly (2-Methoxy, 5-(2’-Ethyl-Hexoxy)-1, 4-Phenylene-Vinylene)] and DP-PPV [Poly (2, 3-DiPhenyl-Phenylene-Vinylene)] is presented through the simulation of the basic equations i.e. the time independent continuity equations, with a drift diffusion form for current density, coupled to Poisson’s equation. Thus, several parameters are extracted from this model; J (V) characteristics for the two devices which are compared to the experimental results and the spatial distributions of the potential, the electric field and the carrier concentrations.Item The Effect Of Ground Albedo On The Performance Gainp And (a-si: H) Of Solar Cells(Oum-El-Bouaghi University, 2014) Mohamed, Chegaar; Guechi, AblaSolar radiation incident on vertical and inclined surfaces consists of beam, sky diffuse and ground reflected components. The ground reflected component may be significant, particularly in the northern latitudes due to low elevations of the sun and, at times, due to the presence of highly reflecting snow cover. Accurate estimation of ground reflected radiation would require knowledge of the foreground type and geometry, its reflectivity and the condition of the sky. The electrical current generated by the solar cells is very sensitive to the incident spectral distribution and intensity. This distribution varies greatly during the day due to changes in the sun’s position or weather conditions. This work investigates the feasibility of using a solar spectral radiation model SMARTS2 to estimate the global solar irradiance on two different sites in Algeria (Setif and Bejaia) and assess the influence of varying ground albedo on the conversion efficiency of GaInP and amorphous (a-Si: H) solar cells. The results show an augmentation in the short circuit current of amorphous (a-Si: H) solar cell due to increasing albedo. It is 6.25% and 9.84% under global radiation and for Setif and Bejaia sites respectively. However for GaInP solar cell, the augmentation of the short circuit current is 6.97% and 10.93% for Setif and Bejaia sites respectively. Nevertheless, the efficiency increases with increasing albedo for GaInP and amorphous (a-Si: H) solar cells.Item Design And Simulation Of A Valveless Piezoelectric Micropump For Fuel Delivery In Fuel Cell Devices(Oum-El-Bouaghi University, 2014) Rihan, YasserMicro- and nano-electromechanical systems (MEMS or NEMS)-based fuel delivery in direct methanol fuel cell (DMFC) devices offer opportunities to address unmet fuel cells related to fuel delivery. By applying an alternating electrical field across the actuator, the resultant reciprocating movement of the pump diaphragm can be converted into pumping effect. Nozzle/diffuser elements are used to direct the flow. To make the power system applicable for portable electronic devices, the micropump needs to meet some specific requirements: low power consumption but sufficient fuel flow rate. In this study, a theoretical method have been used to investigate the effects of materials properties, actuator dimensions, driving voltage, driving frequency, nozzle/diffuser dimension, and other factors on the performance of the whole system. As a result, a viable design of micropump system for fuel delivery in DMFC devices has been achieved and some further improvements are suggested. A mathematical model was used to simulate the behaviour of the micropump. The results of mechanical calculations and simulations show good agreement with the actual behaviour of the pumps.Item Photocatalytic Degradation Of Methylene Blue By Modified Porous Silicon Nanowires(Oum-El-Bouaghi University, 2014) Brahiti, N.; Hadjers, T.; Menari, H.In this paper, the effect of the time deposition of metal nanoparticles on the photodegradation of methylene blue is studied. The modified silicon nanowires were used as heterogeneous photocatalysts for the decomposition of methylene blue under UV light irradiation. The above reactions were monitored by UV–Vis spectrophotometer which shows the positive effect of the time deposition of metal nanoparticles on the photodegradation of methylene blue. 91% of the degradation was observed with the hydrogen terminated porous silicon nanowires and the degradation is about 95% for the modified porous silicon nanowires with Au (80min) and the same degree was obtained with Pt (120min) at 200 minutes of irradiation. The rate of the degradation reaches 100% at 90min of illumination with the decorated porous silicon nanowires with Pd nanoparticles. KeywordsItem Electronic And Structural Properties Of Naznas Compound; An Ab-initio Study In The Tetragonal And Cubic α Phases(Oum-El-Bouaghi University, 2014) Noui, S.; Charifi, Z.; Baaziz, H.; Guezlane, M.theoretical study of structural, and electronic properties of NaZnAs compound is presented by performing ab initio calculations based on density-functional theory using the full-potential linear augmented plane wave (FP-LAPW). The generalized-gradient approximation (GGA) and the local density approximation LDA) are chosen for the exchange–correlation energy. The Engel-Vosko (EVGGA) formalism is applied for electronic properties The calculated structural parameters, such as the lattice constant, bulk modulus and pressure derivative, the electronic band structures and the related total density of states and charge density are presented. The high-pressure α phase of the NaZnAs is investigated and phase transition pressure from tetragonal to high-pressure phase is determined. We have found that the Nowotny–Juza compounds NaZnAs is direct gap semiconductor at ambient pressure. The bonding character and the phase stability of NaZnAs compound are discussed. The nature and the size of the band gap of NaZnAs compound are associated with the bonding character of two Kinds of bonds, namely, Na–As and Zn–As bonds.Item Nanostructured Metallic Oxides Coating(Oum-El-Bouaghi University, 2014) Benhaliliba, MostefaThis project has been focused on structural, morphological, optical and photoluminescence properties of pure ZnO thin film. Here, zinc oxide thin films are grown on glass via facile and low cost sol gel spin coating process @ fixed spinning speed of 1000 RPM. The X-ray patterns, the transmittance, the particle size by the atomic force microscope are investigated. The particle size is equal to 120 nm and the surface roughness is found to be 23.33 nm. The photoluminescence analysis reveals near band emission and strong visible emission 2.11 and 2.80 eV.