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Keffous A.,University of Science and Technology Houari Boumediene | Cheriet A.,University of Science and Technology Houari Boumediene | Belkacem Y.,University of Science and Technology Houari Boumediene | Manseri A.,University of Science and Technology Houari Boumediene | And 9 more authors.
Modern Physics Letters B | Year: 2010

Hydrogenated amorphous SiC films (a-Si1-xCx:H) were prepared by DC magnetron sputtering technique on p type Si(100) and corning 9075 substrates at low temperature, by using 32 sprigs of silicon carbide (6H-SiC). The deposited film a-Si1-xCx:H was realized under a mixture of argon and hydrogen gases. The (a-Si1-xCx:H) films have been investigated by scanning electronic microscopy equipped with EDS system (SEM-EDS), X-rays diffraction (XRD), secondary ions mass spectrometry (SIMS), Fourier transform infrared spectroscopy (FTIR), UV-visible-IR spectrophotometry, and photoluminescence (PL). XRD results showed that the deposited film was amorphous with a structure of a-Si0.81C 0.19:H corresponding to 19 at.% carbon. The photoluminescence response of the samples was observed in the visible range at room temperature with two peaks centered at 463 nm (2.68 eV) and 542 nm (2.29 eV). The structural properties and the origin of the luminescence were discussed. © 2010 World Scientific Publishing Company. Source


Boukezzata A.,University of Science and Technology Houari Boumediene | Nezzal G.,University of Science and Technology Houari Boumediene | Guerbous L.,Algerian Nuclear Research Center | Keffous A.,University of Science and Technology Houari Boumediene | And 6 more authors.
Journal of Luminescence | Year: 2011

Electrochemical etching of amorphous SiC in fluoride solution was studied. Anodic dissolution and passivation are observed for p-type electrodes under dark illumination. The dissolution of p-type a-Si1-xCx is found to be under mixed transport/kinetic control; the diffusion current is of first order in fluoride concentration. Porous etching was not observed in this case. The surface finish of 6H-SiC depends on the experimental conditions; both uniform and porous etching is observed. In this paper, we report the formation of porous p-type amorphous SiC (a-Si1-xCx) films, elaborated previously by DC magnetron sputtering and analyze the porous layers (PSC) using scanning electron microscopy, spectrophotometer and photoluminescence. The crystal structures and the preparation conditions of porous SiC are shown to have an effect on the structural and electrical properties of the material obtained. SEM observation indicates that the porous a-Si1-xCx layers have shown some specific feature; a semi-cylindrical structure of the porous network has been observed. © 2011 Elsevier B.V. All rights reserved. Source


Boukezzata A.,CRTSE | Keffous A.,CRTSE | Gabouze N.,CRTSE | Guerbous L.,Algerian Nuclear Research Center | And 3 more authors.
Microsystem Technologies | Year: 2015

The paper investigates the formation of thin porous amorphous silicon carbide (PASiC) by Al-assisted photochemical etching using HF/AgNO3 solution under UV illumination at λ = 254 nm. Different etching times varying from 2 to 10 min have been used on thin a-Si0.60C0.40:H films, which are elaborated by co-sputtering DC magnetron using a single crystal Si target and who deposited onto 86 of hot pressed polycrystalline 6H-SiC stripes of 12.5 mm3. Because of the high electrical resistivity of the thin a-Si0.60C0.40:H film higher than 2 MΩ cm, and in order to facilitate the chemical etching, a thin metallic film of high purity aluminum (Al) has been deposited under vacuum, follow-up of a thin palladium deposited under a grid to reduce attacked surface and reinforced solution etching. The etched surface was characterized by scanning electron microscopy, infrared spectroscopy, spectrophotometer UV, and photoluminescence. Results show that the morphology of etched a-Si0.60C0.40:H surface evaluates with etching time and presents a spongy and macroporous layers. Where, the diameter of pore size increases with the increasing etching time. A humidity sensors were fabricated through evaporating coplanar interdigital gold electrodes on PASiC and the humidity sensing properties were tested, it show, that the measured resistance Au-PASiC structure, depends highly on the applied bias voltage. Finally, the sensing performances are attributed to the unique surface structure, morphology of the pore and its size, that provide an effective pathway for vapor transportation and enlarged the sensing area of Au-PASiC. © 2015 Springer-Verlag Berlin Heidelberg Source


Keffous A.,University of Science and Technology Houari Boumediene | Cheriet A.,University of Science and Technology Houari Boumediene | Belkacem Y.,University of Science and Technology Houari Boumediene | Gabouze N.,University of Science and Technology Houari Boumediene | And 8 more authors.
Applied Surface Science | Year: 2010

Hydrogenated amorphous SiC films (a-Si1-xCx:H) were prepared by dc magnetron sputtering technique on p-type Si(1 0 0) and corning 9075 substrates at low temperature, by using 32 sprigs of silicon carbide (6H-SiC). The deposited a-Si1-xCx:H film was realized under a mixture of argon and hydrogen gases. The a-Si1-xCx:H films have been investigated by scanning electronic microscopy equipped with an EDS system (SEM-EDS), X-ray diffraction (XRD), secondary ions mass spectrometry (SIMS), Fourier transform infrared spectroscopy (FTIR), UV-vis-IR spectrophotometry, and photoluminescence (PL). XRD results showed that the deposited film was amorphous with a structure as a-Si0.80C0.20:H corresponding to 20 at.% carbon. The photoluminescence response of the samples was observed in the visible range at room temperature with two peaks centred at 463 nm (2.68 eV) and 542 nm (2.29 eV). In addition, the dependence of photoluminescence behaviour on film thickness for a certain carbon composition in hydrogenated amorphous SiC films (a-Si1-xCx:H) has been investigated. © 2010 Elsevier B.V. All rights reserved. Source


Cheriet A.,University of Science and Technology Houari Boumediene | Keffous A.,University of Science and Technology Houari Boumediene | Guerbous L.,Algerian Nuclear Research Center | Belkacem Y.,University of Science and Technology Houari Boumediene | And 2 more authors.
Superlattices and Microstructures | Year: 2012

p-Type porous SiC layers were fabricated by anodization of resistive p-type 6H-SiC samples using HF/ethylene glycol solution. Thin films of lithium (Li) and aluminum (Al) as donor and acceptor elements were vacuum deposited and diffused onto SiC substrates prior to anodization. The aim of this work is to investigate the properties of the nanoporous SiC layer formed by this method and to deduce the effect of diffused lithium as donor and Al as acceptor atoms on their photoluminescence response (PL). The profile distribution of lithium and aluminum diffused atoms was carried out using secondary ion mass spectrometry (SIMS). The photoluminescence spectra of the anodized Al-diffused samples exhibit a broad emission band centered at about 475 nm, while the Li-diffused samples exhibit luminescence with one broad peak located at 655 nm, attributed to Li-related defect centers. In addition, the PL intensity of lithium diffused samples varies with varying the etching time. Finally, the results are expected to have important applications in modern optoelectronic devices and electrode materials of lithium batteries. © 2012 Elsevier Ltd. All rights reserved. Source

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