OMAR Meglali
عمر مقلالي
omar.meglali@univ-msila.dz
0795280886
- Teaching service - Common trunk Nature and Life Sciences
- Faculty of Sciences
- Grade Prof
About Me
Research Domains
Thin films Materials characterization Photovoltaïque energy Chalcopyrite semiconctors Solar cells simulation
LocationMsila, Msila
Msila, ALGERIA
Code RFIDE- 1976-09-22 00:00:00
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OMAR Meglali birthday
- 2025-10-15
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2025-10-15
Electrodeposited ZnO sulfurized into ZnS-ZnO composites as a novel approach for Cd-free buffer layer in chalcogenide solar cells
In this study, ZnS-ZnO composite thin films were developed as alternative buffer layers to CdS and ZnS for second-generation solar cells. ZnO thin films were initially deposited on indium tin oxide (ITO) substrates using the electrodeposition method, followed by sulfurization in sealed glass capsules containing sulfur powder at two different temperatures (500 °C and 550 °C) under an argon-neon atmosphere. The structural, compositional, morphological, and optical properties of the synthesized films were analyzed using grazing incidence X-ray diffraction (GIXRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). X-ray diffraction confirmed the coexistence of both ZnS and ZnO phases, and showed that the proportion of the ZnS phase increases with rising sulfurization temperature. The preferred mechanism for ZnS phase formation is the reaction of ZnO with gaseous sulfur. The Raman spectra of both films sulfurized at 500 °C and 550 °C are nearly identical, displaying the characteristic peaks of ZnS and ZnO. Additionally, ZnS within the composite films is under tensile strain. SEM images reveal that the samples exhibit a highly uniform, homogeneous, and pore-free surface, while XPS confirms the chemical states of Zn, S, and O. These ZnS-ZnO composites exhibit superior structural and optical properties, making them a promising environmentally friendly alternative for buffer layers in chalcogenide solar cells.
Citation
Omar MEGLALI , , (2025-10-15), Electrodeposited ZnO sulfurized into ZnS-ZnO composites as a novel approach for Cd-free buffer layer in chalcogenide solar cells, Physica B: Condensed Matter, Vol:715, Issue:, pages:417611, Elsevier B.V
- 2025-08-15
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2025-08-15
Impact of the pH solution in Cu2O layer for photocatalytic degradation of methyl red by ZnO/Cu2O heterojunction elaborated by double electrodeposition technique
Nowadays, organic dyes are of use in many industries. These dyes are toxic and generally resistant to biodegradation. To face this constraint the use of semiconductor nanoparticles or thin films stand to be an effective alternative. The present contribution deals with the effect of the pH solution on the production of Cu2O thin films for Cu2O/ZnO heterostructure, and its impact on the photocatalytic degradation of methyl red (MR). Heterojunction deposition follows a simple process using two electrodes and only two steps, one for ZnO and the other for Cu20. The results show that ZnO adopts a wurtzite structure along the (101) direction. Cu2O films show a cubic phase at all pH values. Cu2O films develop along the (200) direction at pH = 9.7 and pH = 11.7, for pH = 12.7 the film develop along the (111), with grain size increasing with pH SEM images show a different surface morphology for Cu2O at pH = 12.7, while the cross-section reveals good interlayer adhesion. A better absorption in the UV–visible range, a higher absorption coefficient for Cu2O, and an increase in the optical bandgap with increasing pH. The pH of the Cu2O solution has a significant impact on photocatalytic activity, achieving up to 80 % degradation of MR.
Citation
Omar MEGLALI , , (2025-08-15), Impact of the pH solution in Cu2O layer for photocatalytic degradation of methyl red by ZnO/Cu2O heterojunction elaborated by double electrodeposition technique, Physica B: Condensed Matter, Vol:711, Issue:711, pages:417230, Elsevier B.V
- 2024-10-01
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2024-10-01
Numerical Study and Optimization of a Perovskite Solar Cell Based on Methylammonium Lead Iodide
Provskite solar cells are new devices belonging to the third generation of photovoltaic solar cells. These solar cells are attracting much interest because of their high performance witnessing continuous improvement. In this work, numerical simulations of FTO/NiO/CH3NH3PbI3/(ZnO or TiO2)/Mn perovskite solar cells are performed using AMPS-1D simulator. Two electron transport layers (ETLs) are considered: zinc oxide and titanium oxide. Our perovskite solar cells have brought a wave of innovation to the field of photovoltaics due to their interesting efficiency rivaling established technologies like silicon cells, their simple and low-cost production since that CH3NH3PbI3 can be formed using a spin-coating method, making the fabrication process significantly easier and cheaper compared to traditional techniques. Their excellent light absorption, along with their tunable bandgap are also advantageous parameters. This flexibility allows for tailoring the cell to absorb specific parts of the solar spectrum. The influence of the thickness and the doping concentration in the absorber layer and electron transport layer on the photovoltaic parameters (the short circuit current density Jsc, the open circuit voltage Voc, the fill factor FF and the power conversion efficiency (PCE)) is investigated. The best efficiency performance of 28.2% has been obtained for 300 nm thickness of the absorber layer and 260 nm thickness of TiO2 as electron transport layer and a doping concentration of 1016 cm− 3. The corresponding short-circuit current density is recorded to be 28.81 mA/cm2 whereas the open-circuit voltage is found to be 1.44 V.
Citation
Omar MEGLALI , , (2024-10-01), Numerical Study and Optimization of a Perovskite Solar Cell Based on Methylammonium Lead Iodide, Transactions on Electrical and Electronic Materials, Vol:25, Issue:5, pages:665 - 673, Korean Institute of Electrical and Electronic Material Engineers
- 2023-11-23
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2023-11-23
Effect of ZnO doping co-carried out by Co–Cu on nonlinear optical properties prepared by the spin coating method
In the present work, thin films of ZnO co-doped with Co and Cu cations were obtained on glass substrate, combining the sol gel process and spin-coating technique. For the compound, the general chemical formula used was: Zn1-x-zCoxCuzO, [(x; z) = (0.00; 0.00), (0.02; 0.02), (0.04; 0.04) and (0.06; 0.06)]. For pure ZnO film, the surface morphology is composed by small spherical grains that present interstitial spaces, while the films obtained from the simultaneous Co and Cu insertion in the ZnO structure are more dense and interstitial spaces disappear. For all films, the X-ray diffraction patterns testify the monophasic phase formation, typical of the hexagonal structure of ZnO. In addition, the films presented preferential orientation in the (002) direction. It was demonstrated that the Zn2+ cations by Co2+ and Cu2+ cations replacement, causes relevant modifications in the lattice parameter (c), crystallite size (D), dislocation density (δ), strain (εc) and stress (σc) of the hexagonal structure wurtzite from ZnO. The Co and Cu cations inclusion in the ZnO host lattice, alto caused a decrease in the optical band gap energy (3.37 for 3.16 eV), which is related to the charge transfer between the 4f level electrons and the conduction band or valence band of ZnO. Finally, for all films thin the linear and non-linear optical constants were computed and analyzed, showing variations that depend on the concentration of the dopant cations
Citation
Omar MEGLALI , , (2023-11-23), Effect of ZnO doping co-carried out by Co–Cu on nonlinear optical properties prepared by the spin coating method, Optical and Quantum Electronics, Vol:56, Issue:1, pages:9, Springer
- 2023-07-01
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2023-07-01
Fabrication of ordered layered SnO2/TiO2 heterostructures and their photocatalytic performance for methyl blue degradation
The rapid growth in population and industrialization has given rise to serious environmental issues, especially the water pollution. Photocatalysis with the assist of semiconductor photocatalysts has been considered as an advanced oxidation technique for degrading a variety of pollutants under solar irradiation. In this work, we have fabricated SnO2-TiO2 heterostructures with different ordered layers of SnO2 and TiO2 via the sol–gel dip-coating technique and utilized in photocatalysis for degradation of methyl blue dye under UV irradiation. The influence of the layer’s position on SnO2 and TiO2 properties is investigated via the various techniques. The grazing incidence X-ray diffraction (GIXRD) analysis reveals that the as-prepared films exhibit pure anatase TiO2 and kesterite SnO2 phases. The 2SnO2/2TiO2 heterostructure exhibit the maximum crystallite size and smallest deviation from the ideal structure. Scanning electron microscopy cross-section images manifest good adhesion of the layers to each other and to the substrate. Fourier transform infrared spectroscopy reveals the characteristic vibration modes of SnO2 and TiO2 phases. UV–visible spectroscopy measurements indicate that all films exhibit high transparency (T = 80%) and the SnO2 film reveals a direct band gap of 3.6 eV, while the TiO2 film exhibits an indirect band gap of 2.9 eV. The optimal 2SnO2/2TiO2 heterostructure film revealed best photocatalytic degradation performance and the reaction rate constant for methylene blue solution under UV irradiation. This work will trigger the development of highly efficient heterostructure photocatalysts for environmental remediation.
Citation
Omar MEGLALI , , (2023-07-01), Fabrication of ordered layered SnO2/TiO2 heterostructures and their photocatalytic performance for methyl blue degradation, Environmental Science and Pollution Research, Vol:30, Issue:36, pages:85792 - 85802, Springer Science and Business Media Deutschland GmbH
- 2023-03-04
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2023-03-04
Sulphurization temperature effect on suppressing CuS phase in kesterite CZTS films grown by electrodeposition method
In this study, kesterite Cu2ZnSnS4 thin films were deposited on indium tin oxide substrates by co-electrodeposition method followed with sulphurization at different temperatures. The deposited films are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared and UV–visible spectroscopy. XRD analysis reveals that the films crystallinity is highly influenced by sulphurization temperature, and a temperature of 550°C was sufficient to remove the CuS secondary phase. Moreover, the film sulphurized at 550°C exhibits the lowest lattice strain, the minimal number of crystallites and the highest crystallite size (98.3 nm). However, the films sulphurized at temperature lower than 550°C is composed of kesterite CZTS with CuS as secondary phase. According to the Raman spectroscopy measurments, all films spectra exhibit the intense characteristic line of the CZTS (332 cm–1) assigned to the A symmetry mode. The SEM images reveal that the surface morphology of the films became smooth and void-free as the sulphurization temperature increases. The film sulphurized at 550°C had a suitable bandgap of 1.47 eV, very close to the characteristic values for the pure kesterite CZTS. © 2023, Indian Academy of Sciences.
Citation
Omar MEGLALI , , (2023-03-04), Sulphurization temperature effect on suppressing CuS phase in kesterite CZTS films grown by electrodeposition method, Bulletin of Materials Science, Vol:46, Issue:1, pages:45, Springer
- 2022
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2022
Effet of cobalt doping on the physical properties of ZnO thin films for photocatalytic application
In this work pure and Co doped ZnO thin films have been deposited onto glass substrate at different levels of Co-doping. XRD, SEM, and optical spectroscopy techniques have been used to investigate all films. The grain size was found to increase upon Co doping from 26.2 nm to 50.3 nm.
Citation
MILOUD Ibrir , abdelkader MOHAMMEDI , Omar MEGLALI , ,(2022), Effet of cobalt doping on the physical properties of ZnO thin films for photocatalytic application,1er Séminaire National des sciences du Génie des Procédés,USTHB-Alger
- 2022
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2022
Effet of doping Co-Cu co-doped ZnO on the structural and optical properties prepared by the spin-coating method
Effet of doping Co-Cu co-doped ZnO on the structural and optical properties prepared by the spin-coating method
Citation
MILOUD Ibrir , abdelkader MOHAMMEDI , Omar MEGLALI , ,(2022), Effet of doping Co-Cu co-doped ZnO on the structural and optical properties prepared by the spin-coating method,1st National Conference on Materials, Energy & Environment,Biskra
- 2020
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2020
physics properties of synthesized transition metal (co)-doped zno thin film for photovoltaic application
In this work we prepared the thin films of zinc oxide inlaid with cobalt atoms on glass substrates using sol-gel spin coating technology in different doping concentration (0%, 2% and 3%). Structural optical and electrical properties were studied by XRD, FTIR, UV-visible and quater point respectively. Structural properties showed that the films were well crystallized and had a hexagonal wurtzite crystalline structure with crystalline constants a = b = 3.249Å and c = 5.206Å for pure zinc oxide these values change as the cobalt concentration changes and the grain size were calculated. UV-Visible measurements indicated that the cobalt atomization decreases band gap, the extinction coefficient and refractive index were calculated. Structural, optical and electrical results have shown that thin films and method of preparation can help photovoltaic applications in solar cells and can improve yield for this application.
Citation
abdelkader MOHAMMEDI , MILOUD Ibrir , Omar MEGLALI , AHMED Saoudi , ,(2020), physics properties of synthesized transition metal (co)-doped zno thin film for photovoltaic application,1st international symposium ‘Environment and Sustainable Development’,university of relizan
- 2020
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2020
PHYSICS PROPERTIES OF SYNTH ESIZED TRANSITION METAL (CO)-DOPED ZNO THIN FILM FOR PHOTOVOLTAIC APPLICATION
PHYSICS PROPERTIES OF SYNTH ESIZED TRANSITION METAL (CO)-DOPED ZNO THIN FILM FOR PHOTOVOLTAIC APPLICATION
Citation
MILOUD Ibrir , abdelkader MOHAMMEDI , Omar MEGLALI , ,(2020), PHYSICS PROPERTIES OF SYNTH ESIZED TRANSITION METAL (CO)-DOPED ZNO THIN FILM FOR PHOTOVOLTAIC APPLICATION,1s International Symposium 'Environment & Sustainable Development,Relizane
- 2019
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2019
Optical properties of synthesized metal transition (Fe)-doped ZnO transparent thin films prepared by sol-gel spin coating Solar cells applications
An important milestone in the development of photovoltaic thin-film solar cells is the achievement of conversion efficiences. This work describes the highest efficiency single junction thin-film cell reported to date. n-ZnO/n-CdS/p- CuInSe2 deposited on glass substrate. The current achievements are due to improved properties of ZnO were prepared In this present study, iron doped zinc oxide thin films (ZnO: Fe) were prepared by using a simple chemical sol–gel spin coating technique on the substrate of glass varying the Fe doping concentration 0%, 1%, 5% and 10% wt. Structural and optical properties were studied respectively by X-ray diffraction and UV-visible spectroscopy. Structural results shown that all elaborated thin films are hexagonal wurtzite structure with a preferred orientation along [002] direction. Note that the lattice parameter a=b, c increases while the c constant decreases with the increasing in the Fe concentration. We found that the crystalline size increases with the addition of a Fe, it is achievedby its maximum value 21 nm for 5%. The masses density and the crystals number were calculated, the obtained resultes indicate that they are inversly proportional to the grain size the UV–visible optical transmittance measurements show that films absorption is due to allowed direct transition with a band gap ranged from 3.27 to 3.16 eV.
Citation
abdelkader MOHAMMEDI , MILOUD Ibrir , Omar MEGLALI , AHMED Saoudi , Moufdi. Hadjab, ,(2019), Optical properties of synthesized metal transition (Fe)-doped ZnO transparent thin films prepared by sol-gel spin coating Solar cells applications,The 2nd Algerian-German International Conference on New Technologies and their applications (AGICNT),SETIF - Algeria
- 2019
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2019
Effect (Co) On optical and electrical properties thin films ZnO nanostructure
In this work thin layers of ZnO were prepared with Co cobalt element in different doped concentration, On the substrate of glass prepared by sol–gel spin coating technique Concentration of doped was (0, 1 and 2%). It is for many uses, optical and electrical properties respectively were studied by UV-visible spectroscopy and by EDX by used four points . Where optical studies resulted in the results of the transmittance of the energy gap-band and the extiention coefficient and refractive index figure of merit as the rates of deflection cobalt [1, 2]. As for the electrical results, we studied the effect of the deflection ratios. We determined the electric conductivity and the square resistance. Through the study and the relationship between the optical and electrical properties, the figure of merit was calculated for the Photovoltaic uses.
Citation
abdelkader MOHAMMEDI , MILOUD Ibrir , Omar MEGLALI , ,(2019), Effect (Co) On optical and electrical properties thin films ZnO nanostructure,CONFERENCE INTERNATIONAL DE PHYSIQUE ET CHIMIE QUANTIQUE CIPCQ 2019,Université de Bejaia
- 2019
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2019
Optical properties of synthesized metal transition (Fe)-doped ZnO transparent thin films prepared by sol-gel spin coating Solar cells applications
Optical properties of synthesized metal transition (Fe)-doped ZnO transparent thin films prepared by sol-gel spin coating Solar cells applications
Citation
MILOUD Ibrir , abdelkader MOHAMMEDI , Omar MEGLALI , ,(2019), Optical properties of synthesized metal transition (Fe)-doped ZnO transparent thin films prepared by sol-gel spin coating Solar cells applications,Second Algerian German International on new Technologies and their Applications,Sétif
- 2019
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2019
Effect (Co) On optical and electrical properties thin films ZnO nanostructure
Effect (Co) On optical and electrical properties thin films ZnO nanostructure
Citation
MILOUD Ibrir , abdelkader MOHAMMEDI , Omar MEGLALI , ,(2019), Effect (Co) On optical and electrical properties thin films ZnO nanostructure,3~me Congrés International de Physique et Chimie Quantique,Bijia
- 2018
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2018
Study of structural and optical properties of nanostructure Ni doped ZnO thin films prepared by sol–gel spin coating technique
In this work undoped, thin films and doped ZnO with iron concentrations were deposited on glass substrates by sol-gel spin coating. The doping concentrations of Ni are 0, 2, and 5 (% mol). The structural and optical properties were characterized by X-ray diffraction (XDR) and by UV-visible spectrometry. The results show that all the thin films crystallized in the wurtzaite hexagonal structure with a preferential orientation according to the atomic plane (002). The lattice parameter a has increased and the lattice parameter c decreased as a function of the Ni concentration. We also note that the crystallite size increases with the Ni concentration, with a maximum maximal size was found to be about 24 nm for the film of 5D. As far as optical measurements are concerned, we have found that gap energy (Eg) decreases but Urback energy increases with increasing Ni concentration.
Citation
abdelkader MOHAMMEDI , MILOUD Ibrir , Omar MEGLALI , taieb refice, ,(2018), Study of structural and optical properties of nanostructure Ni doped ZnO thin films prepared by sol–gel spin coating technique,International Conference on Materials Science 2018 (ICMS2018),university of setif 1