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Benramache S.,University Mohamed Khider of Biskra | Chabane F.,University Mohamed Khider of Biskra | Benhaoua B.,El - Oued University Center | Lemmadi F.Z.,University Mohamed Khider of Biskra
Journal of Semiconductors | Year: 2013

This paper examines the growth of ZnO thin films on glass substrate at 350 °C using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are (002) oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 ω·cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 °C has been reported. © 2013 Chinese Institute of Electronics.


Benramache S.,University Mohamed Khider of Biskra | Benhaoua B.,El - Oued University Center | Chabane F.,University Mohamed Khider of Biskra | Guettaf A.,University Mohamed Khider of Biskra
Optik | Year: 2013

Nanocrystalline ZnO thin films are deposited through two different chemical methods: (i) the films prepared by ultrasonic spray with 0.1 M and (ii) dip-coating from zinc acetate complex solutions with 0.5 M, the films obtained at different temperatures. The XRD analyses indicated that ZnO films have nanocrystalline hexagonal structure with (0 0 2) preferential orientation and the maximum crystallite size value of 103 nm measured from the films prepared by dip-coating. UV-vis measurement indicated that all films are transparency in the visible region. The optical band gap increased with decreasing of the Urbach tail energy indicating that the increase in the transition tail width and decrease of the defects, respectively. © 2013 Elsevier GmbH.


Benramache S.,University Mohamed Khider of Biskra | Benhaoua B.,El - Oued University Center
Superlattices and Microstructures | Year: 2012

Transparent conducting indium doped zinc oxide was deposited on glass substrate by ultrasonic spray method. The In doped ZnO samples with indium concentration of 3 wt.% were deposited at 300, 350 and 400 °C with 2 min of deposition time. The effects of substrate temperature and annealing temperature on the structural, electrical and optical properties were examined. The DRX analyses indicated that In doped ZnO films have polycrystalline nature and hexagonal wurtzite structure with (0 0 2) preferential orientation and the maximum average crystallite size of ZnO: In before and annealed at 500 °C were 45.78 and 55.47 nm at a substrate temperature of 350 °C. The crystallinity of the thin films increased by increasing the substrate temperature up 350 °C, the crystallinity improved after annealing temperature at 500 °C. The film annealed at 500 °C and deposited at 350 °C show lower absorption within the visible wavelength region. The band gap energy increased from E g = 3.25 to 3.36 eV for without annealing and annealed films at 500 °C, respectively, indicating that the increase in the transition tail width. This is due to the increase in the electrical conductivity of the films after annealing temperature. © 2012 Elsevier Ltd. All rights reserved.


Benramache S.,University Mohamed Khider of Biskra | Benramache S.,El - Oued University Center | Benhaoua B.,El - Oued University Center
Superlattices and Microstructures | Year: 2012

Pure and Cobalt doped zinc oxide were deposited on glass substrate by Ultrasonic spray method. Zinc acetate dehydrate, Cobalt chloride, 4-methoxyethanol and monoethanolamine were used as a starting materials, dopant source, solvent and stabilizer, respectively. The ZnO samples and ZnO:Co with Cobalt concentration of 2 wt.% were deposited at 300, 350 and 400°C. The effects of substrate temperature and presence of Co as doping element on the structural, electrical and optical properties were examined. Both pure and Co doped ZnO samples are (0 0 2) preferentially oriented. The X-ray diffraction results indicate that the samples have polycrystalline nature and hexagonal wurtzite structure with the maximum average crystallite size of ZnO and ZnO:Co were 33.28 and 55.46 nm. An increase in the substrate temperature and presence doping the crystallinity of the thin films increased. The optical transmittance spectra showed transmittance higher than 80% within the visible wavelength region. The band gap energy of the thin films increased after doping from 3.25 to 3.36 eV at 350°C. © 2012 Elsevier Ltd. All rights reserved.


Benramache S.,University Mohamed Khider of Biskra | Benhaoua B.,El - Oued University Center | Chabane F.,University Mohamed Khider of Biskra
Journal of Semiconductors | Year: 2012

Transparent conducting Co doped ZnO thin films have been fabricated by Ultrasonic spray. The thin films were deposited at three different substrate temperatures of 300, 350 and 400°C. The obtained films had a hexagonal wurtzite structure with a strong (002) preferred orientation. The maximum crystallite size value of the film deposited at 350 °C is 55.46 run. Spectrophotometer (UV-vis) of a Co doped ZnO film deposited at 350 °C shows an average transmittance of about 90%. The band gap energy increased from 3.351 to 3.362 eV when the substrate temperature increased from 300 to 350 °C. The electrical conductivity of the films deposited at 300, 350 and 400 °C were 7.424, 7.547 and 6.743 (Ω·cm) -1 respectively. The maximum activation energy value of the films at 350 °C was 1.28 eV, indicating that the films exhibit a n-type semiconducting nature. © 2012 Chinese Institute of Electronics.


Benhaoua B.,El - Oued University Center | Rahal A.,El - Oued University Center | Benramache S.,University Mohamed Khider of Biskra
Superlattices and Microstructures | Year: 2014

The Al doped ZnO thin films were deposited by ultrasonic spray technique. The influence of Al doping on structural, optical and electrical properties of the ZnO thin films was studied. A set of Al doped ZnO (0-3.5 wt.%) were deposited at 350 C. Nanocrystalline films with a hexagonal wurtzite structure with a strong (0 0 2) preferred orientation were observed after Al doping. The maximum value of grain size (33.28 nm) is attained with Al doped ZnO at 3 wt.%. Texture coefficient TC(h k l) of the four major peaks where evaluated. Optically, in visible region the transmissions spectra T(λ) show that the whole doped films exhibit lower values than the non doped one which has as transmittance more than 80%; whereas in the same region the optical transmissions of the doped films are affected by the doping ration. The band gap (Eg) increased after doping from 3.267 to 3.325 eV with increasing concentration of doping from 0 to 2.75 wt.%, respectively, according to the Burstein-Moss effect (blue shift of Eg) then beyond 3 wt.% in doping the band gap exhibit a slight decreasing due to the coexistence of Roth and Burstein-Moss effect. The electrical resistivity of the films decreased from 20 to 5.26 (Ω cm). The best results are achieved with 2.75 wt.% Al doped ZnO film. © 2014 Elsevier Ltd. All rights reserved.


Benramache S.,University Mohamed Khider of Biskra | Rahal A.,El - Oued University Center | Benhaoua B.,El - Oued University Center
Optik | Year: 2014

Transparent conducting zinc oxide was deposited on glass substrate by ultrasonic spray method. The ZnO samples with concentration of 0.1 M were deposited at 300, 350 and 400 C with 2 min of deposition time. The effects of substrate temperature, ethanol and methanol solution on the structural, electrical and optical properties were examined. The DRX analyses indicated that ZnO films have polycrystalline nature and hexagonal wurtzite structure with (1 0 0) and (0 0 2) preferential orientation corresponding to ZnO films resulting from methanol and ethanol, respectively. The crystallinity of the thin films improved with ethanol solution. All films exhibit an average optical transparency about 80%, in the visible range. The band gap energy of ZnO films obtained with methanol solution higher than of ethanol solution for all the films. The electrical resistivity decrease with ZnO obtained from ethanol indicated; due to the maximum crystallite size retched at this point. © 2013 Elsevier GmbH.


Ydri B.,Annaba University | Ahmim R.,El - Oued University Center
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

In this article, we exhibit explicitly the matrix model (θ=∞) fixed point of φ4 theory on noncommutative spacetime with only two noncommuting directions, using the Wilson renormalization group recursion formula and the 1/N expansion of the zero-dimensional reduction, and then calculate the mass critical exponent ν and the anomalous dimension η in various dimensions. © 2013 American Physical Society.


Dris M.,El - Oued University Center | Djilani B.,El - Oued University Center
International Journal of Renewable Energy Research | Year: 2013

This work presents a theoretical study of maximum power point tracking (MPPT) for photovoltaic (PV) system. The study includes discussion of three MPPT algorithms (the Perturbation and Observation, Incremental Conductance and the Fractional open circuit voltage) and perform comparative tests between them using actual irradiance data. First the PV system with resistive load is discussed, the modelling and the simulation of the PV generator, the DC/DC converter and the three MPPT algorithms are carried out using MATLAB software.


Serhoud H.,El - Oued University Center | Benattous D.,El - Oued University Center
International Journal of Renewable Energy Research | Year: 2012

The aim of this paper is to present the complete modeling and simulation of a grid-connected brushless doubly fed induction generator (BDFG) for variable wind energy conversion is used to assess a maximum power point tracking MPPT strategy for different velocities. The decoupling control of active and reactive powers for BDFG has been developed using PI controllers. The performance of proposed stator power winding flux oriented vector control is examined. The complete system is simulated in the Matlab/Simulink environment and the computer simulation results obtained confirm the effectiveness and validity of MPPT strategy.

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