WEBREVIEW

Two-dimensional Modelling and Simulation of CIGS thin-film solar cell

Amar H., Tobbeche S. — 2015-06-25T08:32:23Z

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  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.

Copper oxide thin films deposition by spray pyrolysis

Aida Mohamed Salah, Attaf N., Lamri Zeggar M. — 2015-06-01T12:06:23Z

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 (...)

- Numéro 01 / Solar cells, Spray pyrolysis, Copper oxide

Channel drop filter based on coupled cavity in photonic crystals

Bendjelloul Rahima, Bouchemat M., Bouchemat Touraya — 2015-06-01T12:01:04Z

In 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 (...)

- Numéro 01 / Photonic crystals, channel drop filter, coupled cavity, wavelength, waveguide

Fabrication, structural and optical characterization of In doped ZnO thin films prepared by the colloidal method

Boudine B., Halimi O., Medjaldi M., Sebais M., Touil O., Zaabat M. — 2015-05-26T11:02:29Z

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.

Effect of a buffer layer on the Performance of Thin-film Cu(In,Ga)Se2 Solar Cells

Dabou R., Khelifi S., Mazari H., Mostefaoui M. — 2015-05-26T10:44:42Z

Copper 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 (...)

- Numéro 01 / Simulation, CIGSe solar cells, buffer layer, SCAPS-1D

Numerical simulation of radiation damage on the device performance of GaAs MESFETs

Beddiafia Y., Dehimi L. , Saadoune Achour — 2015-05-26T10:36:41Z

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 (...)

- Numéro 01 / Simulation, GaAs, defects, silvaco, traps

Effect of Al doping on the properties of electrodeposited ZnO nanostructures

Azizi Amor, Baka Ouidad, Khelladi Mohamed Redha — 2015-05-24T12:15:52Z

In 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).

Morphological and optical properties of sol-gel derived Ni doped ZnO thin film

Benaboud A., Boudine A., Saidani T. , Zaabat M. — 2015-05-24T12:05:35Z

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 (...)

- Numéro 01 / Ni doped ZnO, Thin films ZnO, Optical properties, Sol gel method, dip coating, PACS : 77.55.hF ; 81.20.Fw ; 78.20.-e ; 07.85.Ne ; 68.60.Bs ;

The study of the miniaturisation effect on the characteristics of patch antenna using the WCIP method

Azizi C., Hichem Farh, Mellal S., Zaabat M., Ziar T. — 2015-05-24T10:27:51Z

The 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 (...)

- Numéro 01 / Patch antenna, substrate materials, miniaturization, WCIP method

Structural and magnetic properties of electrodeposited NiFe alloy on silicon nanowires.

Benbrahim N., Bouanik S., Guittoum A., Hadjersi T. , Lamrani S., Mebarki M. — 2015-05-20T12:34:42Z

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 (...)

- Numéro 01 / Structure, Silicon nanowires, NiFe alloy, magnetic properties