Abdelhakim Mahdjoub

Université Larbi Ben Mhidi · sciences de la matière

The aim of the present paper has been to verify the effectiveness and usefulness of a novel deposition process named GIMS (Gas Injection Magnetron Sputtering) used for the flrst time for deposition of Ti/TiO₂ coatings on large area glass Substrates covered in the condition of industrial scale production. The Ti/TiO₂ coatings were deposited in an in...

In this work, a new design of flexible photodetectors based on ZnO/ZnS/PVC composite films was realized using polyvinyl chloride as the polymer substrate. ZnO/ZnS composites were successfully synthesized by a hydrothermal method using a mixture of zinc acetate and thiourea, resulting in the formation of microspheres with a core- shell structure. Th...

Different percentages of CuO and ZnO were added into a local kaolin ceramic-based powder (DD3) with and without ZrO2. The modified powders were first characterized, then, a test for the photocatalytic degradation of dyes with orange II (OII) was carried out. The DD3 powders that were obtained with the addition of ZrO2, ZnO, and CuO, were prepared b...

Undoped and transition metals (TM = Cr, Ni, Mn and Cd) doped zinc oxide (ZnO) thin films were prepared by sol-gel dip-coating method on glass substrates at 300 °C. In this study, the effect of dopant material on the structural, morphological, optical, electrical and mechanical properties of ZnO thin films is investigated by using XRD, AFM, UV-Vis,...

Heavily In doped zinc oxide (IZO) thin films were deposited on glass substrates by dip-coating method with different concentrations of indium. The effect of heavy In doping on the structural, morphological, optical and electrical properties of ZnO was discussed on the basis of XRD, AFM, UV-Vis spectra and Hall effect measurements. The diffraction p...

Thin films of undoped zinc oxide (ZnO) and doped ZnO with copper were deposited on ceramic pellets made from abundant local clay materials with an addition of zirconia (ZrO2). The thin layers were prepared by a thermal method using an autoclave. The resulting structural and morphological properties of the products were studied in order to determine...

Thin films of undoped zinc oxide (ZnO) and doped ZnO with copper were deposited on ceramic pellets made from abundant local clay materials with an addition of zirconia (ZrO2). The thin layers were prepared by a thermal method using an autoclave. The resulting structural and morphological properties of the products were studied in order to determine...

Undoped and heavily indium doped ZnO were deposited by dip-coating sol-gel method on glass substrates. When undoped ZnO was deposited the maximum value of transmittance decreases from 91% for bare substrate to less than 86%. However for ZnO:In coated substrate an unexpected high transmittance of 93.5% was obtained, exceeding that of bare glass subs...

CdS nanocrystalline thin films were synthesized by chemical bath deposition for different deposition times (10–75 min) and the semiconducting and photo-electrochemical properties were investigated. The results indicate that the deposition rate decreases with the deposition time, due to the depletion of Cd²⁺ and S²⁻ ions near the glass subtract. The...

For the preparation of purification elements in our daily life at low cost, thin layers of zinc oxide and ZnO doped with magnesium (0%, 4%, 6%) were deposited on pellets of ceramics constituted cristobalite, mullite and zircon. These substrates are made from local raw materials. The thin films are prepared by dip-coating; their characterization and...

Aiming at purifying water at low cost for our daily life, thin layers of zinc oxide and copper doped ZnO are deposited on ceramic pellets based on cristobalite, mullite and zircon. These substrates are made with local raw material to which zirconia is added so as to create open porosity. The thin films are prepared by sol-gel method. The effect of...

Different percentages of magnesium (5%, 10% and 20%) were added to a local kaolinitic ceramic-based powder (DD3) with and without ZrO 2. Powders were prepared by co-precipitation method. The effect of Mg doping on their structural, morphological and photocatalytic properties has been studied by different analytical techniques such as X-ray diffract...

The improvement of optical confinement on the back crystalline silicon solar cell is one of the factors leading to its better performance. Porous silicon (PS) layer can be used as a back reflector (BR) in solar cells. In this work, single layers of porous silicon were grown by electrodeposition on a single crystalline silicon substrate. The measure...

Porous Cu-doped SnO2 thin films were synthesized by the sol-gel dip-coating method for enhancing methanol sensing performance. The effect of Cu doping concentration on the SnO2 sensibility was investigated. XRD data confirm that the fabricated SnO2 films are polycrystalline with tetragonal rutile crystal structure. AFM and SEM micrographs confirmed...

Graded refractive index silicon oxynitrides are deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD). The analysis of engraving speeds and infrared absorption spectra taken on samples informed us about their chemical compositions. This analysis shows the presence of refractive index gradient. To benefit at...

La recherche dans le domaine des couches minces attire de plus en plus de chercheurs dans le monde. Les propriétés physiques des couches minces nécessitent l’utilisation de différentes techniques de caractérisation. Parmi les plus utilisées, la mesure de la transmittance spectrale des films minces déposés sur substrats transparents permet d’accéder...

A heterojunction based on cadmium sulfide (CdS) deposited on copper and indium selenide (CuInSe2) can be achieved by simple, easy to implement and low cost techniques. Homogeneous CuInSe2 layers were successfully deposited in an electrochemical way. The Raman and XRD analyses confirmed that the deposited films are mostly made of CuInSe2. Transmitta...

A heterojunction based on cadmium sulfide (CdS) deposited on copper and indium selenide (CuInSe 2) can be achieved by simple, easy to implement and low cost techniques. Homogeneous CuInSe 2 layers were successfully deposited in an electrochemical way. The Raman and XRD analyses confirmed that the deposited films are mostly made of CuInSe 2. Transmi...

The influence of the thickness on the optical, structural and morphological properties of CdS thin films elaborated by chemical bath deposition is studied. The deposition time varies between 15 and 75 min and the optical measurements show that the films have high optical transmission (85%). The band gap presents a maximum of 2.44 eV for a depositio...

In this work we used spectroscopic ellipsometry to study the optical properties of thin films deposited on silicon substrates. Analysis of the ellipsometric spectra allows determining the thickness of the deposited films and the dispersion of their optical indices. The proposed method is to develop a theoretical model to calculate the ellipsometric...

A photovoltaic cell, based on copper and indium selenide (CuInSe2) thin layers, with a good efficiency can be achieved by simple, easy to implement and low cost techniques. The high refractive index materials used as absorbers in photovoltaic cells cause high reflection losses (about 30%). Thin CdS and ZnO films that are, respectively, the buffer l...

A photovoltaic cell, based on copper and indium selenide (CuInSe2) thin layers, with a good efficiency can be achieved by simple, easy to implement and low cost techniques. The high refractive index materials used as absorbers in photovoltaic cells cause high reflection losses (about 30%). Thin CdS and ZnO films that are, respectively, the buffer l...

The meso-porous silicon layer (PS) is a promising material to reduce the surface reflectance of solar cells. PS layers were grown on the front surface n+ emitter of n+-p mono-crystalline Si junction. Single layers PS antireflection coating (ARC) achieved around 8% of effective reflectivity in the wavelength range between 400 to 1100 nm. To improve...

The incessant progress in thin layers technology, especially inhomogeneous materials with variable index allows the fabrication of antireflective coating (ARC) less sensitive to the thickness and the incidence angle. Accordingly, our work is devoted to study the optical behaviour of graded refractive index ARC made from: silicon oxynitrides (SiOxNy...

The meso-poreux porous silicon layer (PS) has become an interesting material owing to its potential applications in many fields including optoelectronics and photovoltaics. PS layers were grown on the front surface emitter n+ of n+ -p mono-crystalline Si junction. The thickness of the PS formed and the porosity were measured by an ellipsometer as a...

In this work, several series of ZnO thin films with different deposition parameters were deposited by spray pyrolysis technique. Their optical and electrical properties were analyzed by various techniques. The optical characterization of the films has been performed by UV-Vis spectrophotometry and ellipsometry. The analysis of the transmittance spe...

ZnO thin films were prepared using the simple, flexible and cost-effective spray pyrolysis technique under various experimental conditions. The films' structural, optical and electrical properties were investigated. XRD patterns indicate that the obtained films are polycrystalline in nature with hexagonal würtzite type structure. The films prepared...

ZnO thin films were prepared using the simple, flexible and cost-effective spray pyrolysis technique under various experimental conditions. Their structural, optical and electrical properties were investigated by X-ray diffraction, UV-VIS transmittance spectrophotometry and voltage-current-temperature measurements. The obtained films are polycrysta...

ZnO thin films were prepared using the simple, flexible and cost-effective spray pyrolysis technique under various experimental conditions. Their structural, optical and electrical properties were investigated by X-ray diffraction, UV-VIS transmittance spectrophotometry and voltage-current-temperature measurements. The obtained films are polycrysta...

Thin films with a graded refraction index constituted from silicon and titanium oxides were deposited by plasma enhanced chemical vapor deposition using electron cyclotron resonance. A plasma of oxygen reacted with two precursors: the tetraethoxysilane (TEOS) and the titanium isopropoxide (TIPT). The automatic regulation of the precursor flows make...

Thin films with graded refractive index constituted from silicon and titanium oxides were deposited by plasma enhanced chemical vapor deposition using electron cyclotron resonance. A plasma of oxygen reacted with two precursors: the tetraethoxysilane (TEOS) and the titanium isopropoxide (TIPT). The automatic regulation of the precursors flows makes...

Thin films with graded refractive index constituted from silicon and titanium oxides were deposited by plasma enhanced chemical vapor deposition using electron cyclotron resonance. A plasma of oxygen reacted with two precursors: the tetraethoxysilane (TEOS) and the titanium isopropoxide (TIPT). The automatic regulation of the precursors flows makes...

Condensed polyphosphates close to In(PO 3) 3 structure can be obtained by electrochemical oxidation. These oxides have good dielectric properties and a flexible structure allowing passivation of the fragile surface of indium phosphide. These qualities when added to the low roughness of the interface of 2 to 3 nm taken on this type of treatment may...

The incessant progress in thin layers technology, especially the graded index inhomogeneous dielectrics, allows the realization of antireflection coatings (ARCs). Graded refractive index silicon oxynitrides are deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) controlled in situ by monochromatic ellipso...

Metal-insulator-semiconductor (MIS) structures were produced by electron beam evaporation of Al2O3 on InP. Polyphosphate thin films of thickness 100-150 Å were used to passivate the interface InP\Insulator. Photoluminescence spectra are reported at low temperature at various stages of the realization process of the MIS-InP structure. Photoluminesce...

Metal-insulator-semiconductor (MIS) structures were produced by electron beam evaporation of Al2O3 on InP. Polyphosphate thin films of thickness 100-150 Å were used to passivate the interface InPInsulator. Photoluminescence spectra are reported at low temperature at various stages of the realization process of the MIS-InP structure. Photoluminescen...

By oxidation of InP in liquid medium, condensed indium phosphate In (PO 3)3 could be obtained. In a previous work the physicochemical properties of this compound were studied and it was shown that it could be a good candidate for the passivation of InP. In this work MIS capacitors have been elaborated using this native oxide, C (V ) characteristics...

A new transient characterization technique is used to measure the surface potential shift, interface state density D//i//t and state kinetics for n-InP MIS diodes with a double layer insulator (native anodic oxide-evaporated alumina). The surface Fermi level shift is limited at 0. 35 divided by 0. 55 eV from the conduction band by a steep increase...

The In(PO//3)//3 native oxides appear to have good intrinsic properties to passivate InP due to their chemical, structural, thermodynamical and electrical properties. In this paper the authors summarize these properties and discuss their applicability to the realization of MIS devices.

The InP oxides, obtained electrolytically or by NO3H chemical oxidation were studied in order to analyze the feasibility of implementing with them in MIS electronic devices. The influence of the oxides on the InP/insulator interface was also studied. An MIS structure controlled by photoluminescence was assembled. It is shown that the oxidation prod...