Silicon Technology Development Unit

Algiers, Algeria

Silicon Technology Development Unit

Algiers, Algeria
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Kaci S.,Silicon Technology Development Unit | Keffous A.,Silicon Technology Development Unit | Trari M.,University of Science and Technology Houari Boumediene | Mahmoudi B.,Silicon Technology Development Unit | Menari H.,Silicon Technology Development Unit
Advanced Materials Research | Year: 2011

In this work, we have employed chemical bath deposition (CBD) method to obtain nanocrystalline PbS thin films in the presence of polyethylene oxide (PEO). The spectral response of Au/PbS-pSi(100)/Al Schottky photodiodes at different PEO amount were studied. The response exhibits a combined effect of photogeneration in the heterojunction (HJ) Si side and PbS. Spectral response were observed progressively at shorter wavelength due to the surface absorption. The peak centered at 410 nm properly corresponds to photo-exited holes being injected from PbS to the Si substrate. The intensity of the peak of R(λ) increases with PEO amount, this increasing was attributed to the decreasing of band gap (Eg). © (2011) Trans Tech Publications.


Kaci S.,Silicon Technology Development Unit | Keffous A.,Silicon Technology Development Unit | Guerbous L.,Algiers Nuclear Research Center | Trari M.,University of Science and Technology Houari Boumediene
Thin Solid Films | Year: 2011

PbS nanoparticles and smooth nanocrystalline thin films (nc-PbS) were prepared by chemical precipitation from aqueous solutions. Polyethylene oxide and isopropyl alcohol were used as additives in the aqueous solution, which results in the enhancement of the blue luminescence of PbS thin films. The introduction of isopropyl reduced the grain size and increases the optical gap of the PbS particles. The size of PbS particles was estimated to be ~ 3.5 nm. The broad emission bands exhibited were composed by a multiple overlapping peaks. The photoluminescence (PL) intensity was significantly influenced by the excitation wavelength. Indeed, intense blue luminescence was obtained under 230 nm compared to that obtained under 325 nm excitation wavelength. The PL emission from PbS nanoparticles was less intense than the luminescence of PbS thin films. The high PL intensity of the thin films was attributed to the lower density of defects introduced in the thin films during the chemical bath deposition growth process compared the defects density of PbS powder. © 2011 Elsevier B.V.


Merazga S.,University of Mentouri Constantine | Brighet A.,University of Science and Technology Houari Boumediene | Keffous A.,Silicon Technology Development Unit | Mirouh K.,University of Mentouri Constantine | And 3 more authors.
International Journal of Nanotechnology | Year: 2013

Hydrogenated amorphous silicon carbide thin films (a-SiC:H) were elaborated by DC magnetron sputtering technique by using 6H-SiC as target. The a-SiC:H films of 0.9-1.5 μm thicknesses were deposited at different temperatures of 250, 350, 450 and 550°C on p-type Si(100) and Corning glass 9075 substrates. The deposited films (a-SiC:H) were investigated by Infrared Spectroscopy (FTIR), spectrophotometry (UV-visible-NIR), Secondary Ion Mass Spectrometry (SIMS), and photoluminesence spectroscopy. The previous results of the FTIR measurements reveal the existence of a band located at 775 cm-1, which corresponds to Si-C stretching vibration of SiC amorphous, whereas the Si-C bonds of SiC crystalline is around 810 cm-1. The optical gap varies between 1.9 and 2.10 eV as a function of films' thicknesses and temperature. In addition, the PL spectra of the elaborated films show that the intensity increases when the deposition temperature increases. Copyright © 2013 Inderscience Enterprises Ltd.


Kadouche S.,Université Ibn Tofail | Lounici H.,Polytechnic School of Algiers | Benaoumeur K.,Polytechnic School of Algiers | Drouiche N.,Silicon Technology Development Unit | And 2 more authors.
Journal of Polymers and the Environment | Year: 2012

In this study, synthesize hydroxyapatite (HA) suspensions sedimentation was used after usual terms as support for adsorption of heavy metals ions. Thus, the effectiveness of chitosan, produced from shrimp waste, in the flocculation of turbid suspensions resulting from the treatment of water contaminated with heavy metals was studied by adsorption on HA. Different particles sizes of HA were mainly controlled in this work (an average of granule size ranging from 1. 6 to 63 μm). The results of Cu 2+ and Zn 2+ adsorption on HA showed relatively fast kinetics, with removal extent of 88-95 % by varying the initial total metal concentration. High removal rates were obtained for Cu 2+. Chitosan was found to be able to eliminate by flocculation more than 98 % of turbid suspensions generated by metals adsorption on HA after only 30 min of sedimentation. Effects of pH and dose of chitosan on the coagulation-flocculation process were also studied. The optimal dose of chitosan was found between 0. 2 and 2 mg/L which corresponds to an optimal pH ranging from 6 to 7. © 2012 Springer Science+Business Media, LLC.


Drouiche N.,Silicon Technology Development Unit | Naceur M.W.,Blida University | Ouslimane T.,Silicon Technology Development Unit
CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES | Year: 2012

Reduction of environmental impact and economic cost on the production of photovoltaic panels was studied based on the problem of handling cutting fluid waste (slurry). These fluids are sprayed on the active part of the tool when cutting silicon ingots into thin wafer that form the basic components of solar cells. The cutting fluidwere treated by centrifugation at ambient temperature, but the use of this technique proved its low efficacy. An ultrafiltration through a polyethersulfone membrane with a cutoff of 1kDa showed excellent efficacy and affinity vs. the oil (HS20) to be considered, allowing its full recovery by maintaining its original cutting fluid characteristics. However, some drawbacks were observed using this technique. Reinforcement of ultrafiltration - in the same operating Conditions - by a chemical pretreatment was considered. A lower fouling index and a permeation flux comparable to that observed for virgin cutting fluid was obtained. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).


Drouiche N.,Silicon Technology Development Unit | Ghaffour N.,King Abdullah University of Science and Technology | Naceur M.W.,Blida University | Mahmoudi H.,University of Hassiba Ben Bouali Chlef | And 2 more authors.
Water Resources Management | Year: 2011

Seawater/brackish water desalination has been widely adopted by the Algerian Government in the last few years to supply potable water to municipality for various purposes mainly for domestic and industrial uses especially in areas where demand is high due to shortage of fresh water resources, rapid population growth and development of industry and tourism. Ten years ago, desalination was confined to the industrial use only especially in oil and gas industry as the country was relying on rain water and other available sources to supply fresh water to municipalities. Due to chronic drought conditions, the Ministry of Water Resources reviewed the national water strategy and a strong option for desalination was adopted where an ambitious program was thus put into action. Sixteen mega-plants, with capacities ranging from 100,000 to 500,000 m3 per day, primarily based on Reverse Osmosis technology, were launched in the last few years making the Algerian desalination program one of the world's fastest growing markets. Five desalination plants, including the Africa's largest seawater reverse osmosis project with a total capacity of 200,000 m3 per day, are already in operation and the remaining projects are either under construction or in commissioning. An integrated water resources management was also adopted as additional option to cuter the increasing water demand as there is also a great potential for water reuse and conventional water treatment. An additional benefit of this would be reducing the volume of treated wastewater disposed into the environment. © 2011 Springer Science+Business Media B.V.


Drouiche N.,Silicon Technology Development Unit | Drouiche N.,King Abdullah University of Science and Technology | Ghaffour N.,King Abdullah University of Science and Technology | Naceur M.W.,Blida University | And 2 more authors.
Desalination and Water Treatment | Year: 2012

Algeria aspires to protect its water resources and to provide a sustainable answer to water supply and management issues by carrying out a national water plan. This program is in line with all projects the Algerian Government is implementing to improve its water sector performance. The water strategy focuses on desalination for the coastal cities, medium-sized dams to irrigate the inland mountains and high plateau, and ambitious water transfer projects interconnecting Algeria's 65 dams to bring water to water scarce parts of the country. Waste water treatment and water reclamation technologies are also highly sought after. The main objective of the country's water policy consists on providing sufficient potable water for the population supply. This objective is undertaken by increasing the water resources and availability. © 2012 Desalination Publications. All rights reserved.


Fellahi O.,Silicon Technology Development Unit | Hadjersi T.,Silicon Technology Development Unit | Maamache M.,Ferhat Abbas University Setif | Bouanik S.,Silicon Technology Development Unit | Manseri A.,Silicon Technology Development Unit
Applied Surface Science | Year: 2010

The morphology of silicon nanowire (SiNW) layers formed by Ag-assisted electroless etching in HF/H2O2 solution was studied. Prior to the etching, the Ag nanoparticles were deposited on p-type Si(1 0 0) wafers by electroless metal deposition (EMD) in HF/AgNO3 solution at room temperature. The effect of etching temperature and silicon resistivity on the formation process of nanowires was studied. The secondary ion mass spectra (SIMS) technique is used to study the penetration of silver in the etched layers. The morphology of etched layers was investigated by scanning electron microscope (SEM). © 2010 Elsevier B.V.


Khelifati N.,Silicon Technology Development Unit | Khelifati N.,University of Boumerdès | Bouhafs D.,Silicon Technology Development Unit | Boumaour M.,Silicon Technology Development Unit | And 2 more authors.
Materials Science in Semiconductor Processing | Year: 2012

We have investigated the extended phosphorus diffusion gettering (PDG) effect on chromium impurities (Cr) in p-type multicrystalline silicon (mc-Si) grown by Heat Exchanger Method (HEM). The study was made after phosphorous diffusion and according to different extended annealing temperatures. The secondary ion mass spectrometry (SIMS) analysis revealed a significant accumulation of 52Cr in heavily phosphorus doped (HPD) region. Using quasi-steady state photoconductance (QSSPC) technique, the apparent lifetime dependent minority carrier density curves have been obtained. The results showed an increment of the bulk minority carrier lifetime for specific annealing temperatures. Appropriate calculations based on QSSPC results allowed us to determine the lifetime curves associated to gettered impurities. Their fitting by Shockley-Read-Hall (SRH) model reveal that the origin of the lifetime increment is the reduction of interstitial chromium (Cr i) density in the bulk. Furthermore, the estimation of electron to hole capture cross-section ratio (k=σ n/σ p) through the modelling of apparent lifetime curves using Hornbeck-Haynes model, confirmed the effectiveness of Cr i gettering and identified the nature of dominant recombination centres after gettering process. © 2011 Elsevier Ltd. All rights reserved.


Drouiche N.,Silicon Technology Development Unit | Drouiche N.,Polytechnic School of Algiers | Naceur M.W.,Blida University | Boutoumi H.,Blida University | And 3 more authors.
Desalination and Water Treatment | Year: 2013

The main objective of the work was to regenerate a cutting fluid HS20 used in the manufacturing of silicon wafers. Centrifugation at ambient temperature is initiallyconsidered for the treatment of the cutting fluid HS20. However, the slurry being heavily loaded with mineral colloids, tests conducted following the use of this process, have proved its efficiency to be low. Indeed, the best results for colloidal matter abatement have never exceeded 30%. By contrast, an ultrafiltration through a polyethersulfone membrane with a cutoff of 1 kDa shows excellent efficiency and affinity towards the fluid (HS20) to be considered, allowing its full recovery by maintaining its original cutting fluid characteristics. However, this process does present some drawbacks. A strong resistance to flow across the membrane of up to 60% of the total resistance is observed and a drop in permeation flux of about 90% are observed. Given these results, reinforcement of ultrafiltration, under the same operating conditions, by chemical pretreatment is considered. Chemical pretreatment with ultrafiltration offers better regeneration efficiencies under same flow conditions through the membrane as compared to an ultrafiltration process. Indeed, the fouling index is significantly reduced to around 153 × 10+s/L and a permeation flux comparable to that observed for virgin cutting fluid (HS20) is obtained. © 2013 Desalination Publications.

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