SAMIR Hamrit

Djaadi rabab

Elaboration et caracterisation des couches minces de ZnO par la technique spray pyrolyse.

KERFAL Amani

Deposition and characterization of undoped and Al doped Zinc Oxide thin films using spray pyrolysis technique

MANSOURI Mouna

Solvothermal synthesis and caraterisation of doped ZnO nanoparticules

Alili Asma , Belhout Awatef

Synthèse des nanomatériaux d’oxydes métallique par la méthode solvothermale

HASBAIA Mariem

Étude de l’effet de l’épaisseur sur les propriétés structurales et optiques des couches minces de ZnO:Al

KHERIFI Oumhani

Étude des propriétés physico-chimiques des nanopoudres de ZnO:Al synthétisées par le procédé Sol-Gel

Wafa AOUINA

Etude des propriétés structurales, optiques et électriques des oxydes transparents conducteurs nanostructurés de ZnO dopé Al.

Solvothermal Synthesis and Characterization of Undoped and Cu-Doped ZnO Nanoparticles: Structural and Elemental Analysis.

Citation

SAMIR Hamrit , ,(2024-12-02), Solvothermal Synthesis and Characterization of Undoped and Cu-Doped ZnO Nanoparticles: Structural and Elemental Analysis.,The 1st national conference on physics and its application,ENS BOUSAADA

This paper reports the synthesis of exfoliated structure of Poly-methylmethacrylate/organomontmorillonite nanocomposites by in situ polymerization of Methylmethacrylate monomer as a cost-efective adsorbent for ultrahigh removal of azo dye pollutant from aqueous media. The obtained nanocomposites with diferent organoclay loading (1–7 mass%) were characterized by XRD, FTIR, DTA, TGA, TEM and SEM. In the XRD results, the observation of small pick shoulders (d001) and almost no refection in the X-ray difractrograms indicated, respectively, the establishment of intercalated/exfoliated structures and major exfoliation of OMMT clay into polymer. This observation was supported by TEM microscopy. TGA results revealed improved thermal properties in comparison with the pure polymer. Adsorption parameters such as pH-value, contact time and initial dye concentration were investigated to assess optimum adsorption activity. The adsorption experiments showed that the equilibrium time of adsorption was reached very rapidly. According to the kinetic study, the adsorption process followed pseudo-second-order model. The adsorption capacity is unafected by variation of solution pH. The high maximum adsorption capacity of PMMA/OMT nanocomposite toward dye was found to be 309.6 mg g−1. Langmuir isotherm was more suitable model to describe the adsorption of dye than Freundlich and Dubinin–Radushkevich models. Thermodynamic study showed that the removal of the azo dye from aqueous solution by PMMA/OMT nanocomposite is endothermic nature, spontaneous and physisorption process. Under three adsorption–desorption cycles, PMMA/OMT nanocomposite had good re-adsorption efect. Thus, PMMA/OMT nanocomposite can be an efcient and recyclable adsorbent for azo dyes.

Citation

SAMIR Hamrit , , (2024-01-13), Synthesize of exfoliated poly‐methylmethacrylate/ organomontmorillonite nanocomposites by in situ polymerization: structural study, thermal properties and application for removal of azo dye pollutant, Journal of Thermal Analysis and Calorimetry, Vol:128100, Issue:23, pages:128100, Springer

Nanostructured trqnspqrent conductive oxide Ql doped ZnO thin films onto glass substrates deposited by RF magnetron sputtering fro, nanopowder target

Citation

SAMIR Hamrit , ,(2023-12-02), Nanostructured trqnspqrent conductive oxide Al doped ZnO thin films onto glass substrates deposited by RF magnetron sputtering fro, nanopowder target,the first national conference on physics and it's applications,ENS BOUSAADA

Zinc oxide is an important oxide semiconductor, with excellent physical and chemical properties that are used in different applications fields. In this research paper, ZnO thin films were synthesized using different types of solvent by sol-gel spin coating technique. The effect of solvent on the structural, morphological, photocurrent and optical properties of the films has been studied. X-ray diffraction revealed the high crystallinity of films in the wurtzite structure with a c-axis preferred orientation. SEM micrographs revealed that all films exhibit a fibrous structure, where the more homogeneous and dense surfaces were observed for ZnO-2-PrOH and ZnO– EtOH films. The optical properties analysis shows that the films have high transparency. Different structural and optical parameters were influenced by the type of solvent, where ZnO-2-PrOH film displays an improvement in structural and optical properties. The photoluminescence PL spectrum revealed three emissions, two green emissions and a UV emission at 390 nm. ZnO-2-PrOH film exhibits a high intensity ratio of UV to visible (IUV/ Ivis), a best UV response, and photocurrent properties. Finally, structural and optical parameters were also calculated by first-principles DFT calculations, discussed, and compared to those experimental.

Citation

Djamel ALLALI , Abdelhafid MAHROUG , SAMIR Hamrit , , (2023-06-16), Optical, luminescence, photocurrent and structural properties of sol-gel ZnO fibrous structure thin films for optoelectronic applications: A combined experimental and DFT study, Optical Materials, Vol:142, Issue:, pages:114043, Elsevier

Zinc oxide is an important oxide semiconductor, with excellent physical and chemical properties that are used in different applications fields. In this research paper, ZnO thin films were synthesized using different types of solvent by sol-gel spin coating technique. The effect of solvent on the structural, morphological, photocurrent and optical properties of the films has been studied. X-ray diffraction revealed the high crystallinity of films in the wurtzite structure with a c-axis preferred orientation. SEM micrographs revealed that all films exhibit a fibrous structure, where the more homogeneous and dense surfaces were observed for ZnO-2-PrOH and ZnO–EtOH films. The optical properties analysis shows that the films have high transparency. Different structural and optical parameters were influenced by the type of solvent, where ZnO-2-PrOH film displays an improvement in structural and optical properties. The photoluminescence PL spectrum revealed three emissions, two green emissions and a UV emission at 390 nm. ZnO-2-PrOH film exhibits a high intensity ratio of UV to visible (IUV/Ivis), a best UV response, and photocurrent properties. Finally, structural and optical parameters were also calculated by first-principles DFT calculations, discussed, and compared to those experimental.

Citation

SAMIR Hamrit , , (2023-06-13), Optical, luminescence, photocurrent and structural properties of sol-gel ZnO fibrous structure thin films for optoelectronic applications: A combined experimental and DFT study, Optical Materials, Vol:142, Issue:, pages:114043, Elsiver

Due to its excellent physical and chemical properties, transition metal-doped zinc oxide has potential applications in different fields. In this research paper, pure and iron-doped ZnO films were deposited by thermal oxidation of sputtered metallic zinc and iron. The effect of iron (Fe) doping on the optical, morphology, structural, electrical, and photocurrent properties of zinc oxide films was examined. The X-ray diffraction analysis shows a wurtzite structure with preferential orientation for all films, where the high texture coefficient values (above 3) corresponded to the (002) plane. Fe doping reduced the crystallite size from 12.3 to 8.7 nm and lattice constants c and a values from 5.19 to 5.155 Å and from 3.236 to 3.203 Å respectively. The different calculated structure parameters, confirm the incorporation of Fe (Fe3+) in the ZnO lattice. The surface morphology of thin films measured using atomic force microscopy revealed that the Fe doping could markedly decrease the grains size from 248 to 54 nm and the Root–Mean–Square roughness of films from 5.27 to 4.22 nm. For all films, the transmittance analysis shows a transmittance above 90% in the visible region and with an increase in the Fe concentration, the transmittance, and the absorption in the ultraviolet region were increased. The gap energy of ZnO strongly increased from 3.26 to 3.51 eV with doping. The effect of Fe doping on different optical parameters was discussed in detail. The photoluminescence analysis of pure and doped ZnO exhibits one ultraviolet emission (384 nm) and green emission. Compared to pure ZnO, the ultraviolet peak intensity decreased as Fe content increased. The electrical resistivity was decreased and the photocurrent properties of ZnO were enhanced by Fe doping. In this report, Fe-doped ZnO films exhibited remarkable properties. Therefore such films can be usefully used in different device applications.

Citation

SAMIR Hamrit , , (2023-04-19), Optical, Photocurrent, Electrical, Structural, and MorphologicalProperties of Magnetron Sputtered Pure and Iron-Doped ZincOxide Thin Films, characterized by the Root–Mean–Square (RMS) parameter and thevalues of average grain size. The resistivity was determined by thecurrent-tension measurements. The photocurrent measurements weredone in an electrochemical cell (λUV = 365 nm).Results and Disc, Vol:12, Issue:4, pages:046006, IOP Publishing

As an important metal oxide semiconductor, transition metal-doped zinc oxide (ZnO) has attracted great interest for various applications in optoelectronic, spintronic photovoltaic and photodetectors due to its significant chemical and physical properties. In this research study, pure and nickel (Ni)-doped ZnO nanostructured films were synthesized via the sol-gel method using the spin coating technique on glass substrates. The structural results revealed that all samples exhibited a polycrystalline wurtzite structure and a (002) plane preferred orientation. The crystallite size was reduced by Ni doping. The morphology micrographs indicate that the surface of thin films shows nanofiber structures. An optical study revealed the high transparency of the films. The photoluminescence (PL) showed one ultraviolet (UV) emission at 387 nm and different defect emissions for all films. The absorption, band gap and PL emissions intensities were influenced by Ni doping. Ni-doped ZnO nanostructured thin films revealed high UV sensitivity and photoresponse. Therefore, these thin films are a promising material for a UV photodetector. The dielectric function, absorption coefficient and energy band gap were also calculated and discussed by density functional theory (DFT), using the Ultra Soft Pseudo Potential (USPP) approach implemented in the CASTEP code.

Citation

SAMIR Hamrit , , (2022), Experimental and DFT study of structural and optical properties of Ni-doped ZnO nanofiber thin films for optoelectronic applications, Optical Materials, Vol:134, Issue:134, pages:113-188, Elsivier

RF-magnetron sputtering has been carried out at room temperature to deposit vanadium-doped zinc oxide (VZO) nanostructured thin films onto flexible PEN substrates. The sputtering targets of compacted VZO nanopowder have been prepared using a rapid and inexpensive Sol-Gel synthesis followed by a supercritical drying process. Structural and morphological study of VZO particles in the targets has been carried out via X-ray diffraction and Transmission Electron Microscopy (TEM). The nanostructured thin films have been characterized to analyze the structural, morphological, electrical and optical properties as a function of vanadium content from 0 to 4 at.%. Structural characterization of VZO thin films revealed that the deposited thin films have been grown preferentially along (002) and exhibit the hexagonal wurtzite structure. The cross-sectional and microstructural analysis performed by Scanning Electron Microscopy (SEM) confirms the columnar growth of nanostructures. The deposited thin films exhibit transparent behavior with transmission >70% in the visible region. It has been observed that nanostructured thin films with vanadium content of 2% have demonstrated the lowest resistivity (6.71 × 10􀀀 4 Ω cm) with Hall mobility of 10.62 cm2 V􀀀 1 s􀀀 1. The deposited vanadium doped nanostructured thin films would have potential applications in electronic and optoelectronic devices.

Citation

SAMIR Hamrit , , (2021), Realization of high transparent conductive vanadium-doped zinc oxide thin films onto flexible PEN substrates by RF-magnetron sputtering using nanopowders targets, Ceramics International, Vol:47, Issue:47, pages:22881-22888, Elsivier

In this work, nanostructured vanadium doped zinc oxide (VZO) thin films were deposited by rf­magnetron sputtering onto flexible PEN substrates at room temperature. The compacted VZO nanopowder, which was synthesized by the sol­gel method combined with a supercritical drying process, was used as target in the sputtering system. Characterization results of the VZO nanoparticles show a typical hexagonal wurtzite structure without any secondary phases. The average size of nanoparticles was ranged from 30 to 40 nm observed with Transmission Electron Microscopy (MET). The structural, electrical and optical properties of the VZO thin films were investigated as a function of V­doping amount (0 ­ 4 at.%) in the nanopowder target. X­ray diffraction results indicate that the deposited thin films have a hexagonal wurtzite structure with c­axis orientation without any secondary phases. The Scanning Electron Microscopy (SEM) cross section image revealed that the films have a columnar nanostructure. The optimum doping amount in the target to achieve the minimum film resistivity and the maximum film transmission was observed for 2 at.% of V. The electrical resistivity of 500 nm­thick VZO film was ̴ 5.x10­4 Ω.cm with Hall mobility of 16 cm2.V­1.s­1. The average transmission in the visible range was higher than 70 %.

Citation

SAMIR Hamrit , Kamal Djessas, Kahina Medjnoun, ,(2017), NANOSTRUCTURED TRANSPARENT CONDUCTIVE OXIDE V DOPED ZNO THIN FILMS DEPOSITED ONTO FLEXIBLE PEN SUBSTRATES BY RF­ MAGNETRON SPUTTERING FROM NANOPOWDER TARGET,8th International Conference on Innovations in Thin Film Processing and Characterization 23-27 October 2017 - Campus ARTEM, Nancy (France),Nancy (France)

In this study, we have used RF-magnetron sputtering to deposit Al-doped ZnO (AZO) nanostructures thin films on poly-ethylene naphthalate (PEN) substrates. The compacted AZO nanopowders with different Al concentrations (0, 1, 2, 3 and 4 at.%), which were synthesized by sol–gel method combined with a supercritical drying process, have been used as targets. Structural, optical and electrical properties of deposited thin films with different Al concentrations have been investigated. X-ray diffraction results indicated that all the deposited thin films have hexagonal wurzite structure with c-axis orientation without any secondary phases. The SEM cross section image of the films revealed very dense columnar nanostructure. The best electrical properties (ρ = 4 × 10−4 Ω cm, µ = 22 cm2 V−1 s−1, and ne = 8 × 1E20 cm−3) were obtained for the AZO samples containing 2 at.% of Al. The thin films show an average transmittance of 80 % with the PEN substrate in the visible region.

Citation

SAMIR Hamrit , Kamal DJESSAS, Noureddine BRIHI, Olivier BRIOT, Matthieu MORET, Zouhaier BENAYADI, , (2016), Study and optimization of Al-doped ZnO thin films deposited on PEN substrates by RF- magnetron sputtering from nanopowders targets, Journal of Materials Science: Materials in Electronics, Vol:27, Issue:2, pages:1730-1737, Springer

Nanostructured aluminum-doped ZnO (ZnO:Al) thin films of various thicknesses were deposited on flexible Poly-Ethylene Naphthalate (PEN) substrates by RF-magnetron sputtering without intentionally heating them to fabricate Transparent Conductive Oxides (TCOs). The compacted ZnO:Al nanopowder with an [Al]/[Zn] ratio of 2%, which was synthesized by the sol-gel method combined with a supercritical drying process, was used as target in the sputtering system. The structural, morphological, optical and electrical properties of the deposited thin films of various thicknesses have been investigated. X-ray diffraction results indicate that all of the deposited thin films have a hexagonal wurtzite structure with c-axis orientation without any secondary phases. The Scanning Electron Microscopy (SEM) cross section images revealed that the films have a dense columnar nanostructure. The atomic percentage of the compositional elements in the films was nearly the same as that in the sputtering nanopowder target. Below a critical thickness of 500 nm, the films exhibit a high transmittance (>77% including the contribution of the PEN substrate) in the visible region. However, the electrical resistivity, Hall mobility and carrier concentration were significantly affected with the increase of film thickness. For thicknesses higher than 500 nm, the thin films exhibit similar electrical properties (resistivity of 3.5×10−4 Ω cm and Hall mobility of 22 cm2 V−1 s−1) but the transmittance decreases in the visible region. The Photoluminescence spectra showed that the Zn interstitial atoms, which enhance the conductivity of the films, are more dominant than the other defects.

Citation

SAMIR Hamrit , Kamal DJESSAS, Noureddine BRIHI, B. Viallet, Kahina Medjnoun, Stefano E. Grillo, , (2016), The effect of thickness on the physico-chemical properties of nanostructured ZnO:Al TCO thin films deposited on flexible PEN substrates by RF- magnetron sputtering from a nanopowder target, Ceramics International, Vol:42, Issue:14, pages:16212-16219, Elsevier

In the present study, the thermally exfoliated vermiculite has been sonicated in order to grafting with the butyl-imidazolium. A suspension of vermiculite-water with 1% of concentration was sonicated at 20 KHz. This led to the decrease in the size of grains to16 µm after 2 h of treatment. Increasing of sonication time, presence of H2O2, and the increase of the vermiculite concentration have caused an accentuation of sonication effect, this resulted the decreasing of the size to 10 µm. Moreover, a 2% fraction of submicron-sized particles was appeared. The pH of the vermiculite suspensions was increased. The number of the -OH sites was determined by acid-base titration using Gran method. The infrared spectra of the raw and sonicated vermiculites in H2O or containing H2O2 were very similar. In the presence of H2O2, two bands were observed at 1380 and 1460 cm -1 . These are due to the presence of carbonates anions formed during sonication in H2O2. XRD spectra showed that the sonication did not affect the vermiculite structure. The grafting was carried out on sonicated samples during 5 h in H2O. This was realized in two steps. In the first step, we grafted 3-chloropropyltrimethoxysilane instead of the –OH sites. In the second step, we conducted a nucleophilic substitution of chlorine with methyl-imidazole. We proved by infrared spectroscopy and Gran method that grafting was real and XRD that this was not an intercalation

Citation

Smail TERCHI , SAMIR Hamrit , Brahim Kebabi, Hassina Bougherara, Boubebekeur Boudine, , (2016), Modification of the Thermally Exfoliated Vermiculite by Sonication and Grafting Methods, Journal of New Technology and Materials, Vol:6, Issue:2, pages:72-80, O.E.B Univ. publish. Co

Undoped and Al-doped ZnO thin films have been deposited onto glass substrates by the sol–gel spin coating method and their structural and optical properties have been investigated. The XRD results showed that all films were crystallized under hexagonal wurtzite structure and presented a preferential orientation along the c-axis where the maximum crystallite size was found to be 25 nm for undoped film. The average transmittance of all films is over 95% in the visible region and the band gap energy increases from 3.25 to 3.29 eV with the increase of Al concentration. In addition to the vibrational modes from undoped ZnO, longitudinal optical (LO) mode in the Raman spectra was enhanced by the Al doping. Photoluminescence of the films showed an ultraviolet (UV) and defect related visible emissions like violet, blue and green. 3% Al doped ZnO film shows the best photocurrent properties.

Citation

Abdelhafid MAHROUG , SAMIR Hamrit , S. Boudjadar, Lakhdar Guerbous, , (2014), Structural, optical and photocurrent properties of undoped and Al-doped ZnO thin films deposited by sol–gel spin coating technique, Materials letters, Vol:134, Issue:1, pages:248–251, Elsevier

Undoped and Co-doped ZnO thin films with different amounts of Co have been deposited onto glass substrates by sol–gel spin coating method. Zinc acetate dihydrate, cobalt acetate tetrahydrate, isopropanol and monoethanolamine (MEA) were used as a precursor, doping source, solvent and stabilizer, respectively. The molar ratio of MEA to metal ions was maintained at 1.0 and a concentration of metal ions is 0.6 mol L−1. The Co dopant level was defined by the Co/(Co + Zn) ratio it varied from 0 to 7 % mol. The structure, morphology and optical properties of the thin films thus obtained were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDX), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis), photoluminescence (PL) and Raman. The XRD results showed that all films crystallized under hexagonal wurtzite structure and presented a preferential orientation along the c-axis with the maximum crystallite size was found is 23.5 nm for undoped film. The results of SEM indicate that the undoped ZnO thin film has smooth and uniform surface with small ZnO grains, and the doped ZnO films shows irregular fiber-like stripes and wrinkle network structure. The average transmittance of all films is about 72–97 % in the visible range and the band gap energy decreased from 3.28 to 3.02 eV with increase of Co concentration. DRX, EDX and optical transmission confirm the substitution of Co2+ for Zn2+ at the tetrahedral sites of ZnO. In addition to the vibrational modes from ZnO, the Raman spectra show prominent mode representative of ZnyCo3−yO4 secondary phase at larger values of Co concentration. PL of the films showed a UV and defect related visible emissions like violet, blue and green, and indicated that cobalt doping resulted in red shifting of UV emission and the reduction in the UV and visible emissions intensity.

Citation

SAMIR Hamrit , Abdelhafid MAHROUG , S. Boudjadar, L. Guerbous, , (2014), Structural, morphological and optical properties of undoped and Co-doped ZnO thin films prepared by sol–gel process, Journal of Materials Science: Materials in Electronics, Vol:25, Issue:11, pages:4967–4974, springer