BAHRI Deghfel

SALIM BENAICHE

Contribution à l’étude de la dynamique non linéaire d’un plasma poussiéreux hors équilibre thermodynamique

Ammar BOUKHARI

Elaboration, characterization and modeling of oxide-based nanostructured thin films

Benrezgua Elhadj

Synthèse, caractérisation et étude des propriétés de nanocomposites à base d'oxyde de zinc

Amari Rabie

Etude de l'effet de dopage sur les propriétés physiques et chimiques des semi-conducteurs à base d’oxyde synthétisées par la technique sol gel-spin coating

Bendjedi Ahlam

Etude des paramètres d'interaction des rayonnements ionisants avec la matière en vue des applications analytiques

MEHDDEB Asma

Study of the structural, electronic, elastic and optical properties of the CuFeO2 compound

ABDELLAHOUM Leila

Calculation of structural, electronic, elastic and optical properties of 2H-CuGaO2: First principle study

ROUBACHE Besma

Etude des propriétés structurales, électroniques, élastiques et optiques du composé 3R- CuGaO2

DECHOUCHA, SAMIYA

Sections efficaces semi-empiriques de production des couches M des éléments de numéros atomiques 60  Z  90 par des protons en vue des applications analytiques

Metal oxides in nanostructured powder and thin-film forms are vital due to their unique physicochemical properties. This talk discusses advanced synthesis methods such as chemical (sol-gel, hydrothermal, electrodeposition) and physical techniques (sputtering, laser deposition, thermal evaporation). Focus will be on modern characterization tools like SEM, XRD, and UV-Vis spectroscopy for structural, compositional, and functional assessment. Applications in wastewater treatment, particularly photocatalysis and adsorption, will be highlighted, with examples on degrading persistent organic compounds and improving parameters like chemical oxygen demand (COD). The goal is to present these advanced oxides as sustainable solutions for environmental challenges.

Citation

Bahri DEGHFEL , ,(2025-02-17), Powder and Thin Film Oxides: Advanced Chemical and Physical Elaboration Methods, Characterization, and Applications for Wastewater Treatment,The 2ⁿᵈ National Seminar of Physics, Chemistry and their Applications NSPCA' 25,:'برج بوعريريج الجزائر

This study aims to prepare manganese-doped zinc oxide (MZO) thin films with low Mn content (x = 0, 2, 4 %) using the sol–gel spin coating method and to characterize their structural, optical, and magnetic properties. Experimental techniques were complemented by Density Functional Theory calculations with Hubbard correction (DFT-LDA + U). All films exhibit a polycrystalline wurtzite hexagonal phase of ZnO. As the Mn doping increases, all diffraction peaks are getting weaker, which leads to deterioration in the crystallinity of the samples. Furthermore, Mn doping affects the grain size (57.44–38.20 nm), the surface morphology (rms: 45.24–30.47 nm), the transmittance (93–54 %) and the optical band gap energy (Eg: 3.27–3.18 eV). Photoluminescence spectra reveals ultraviolet peaks (386–395 nm) along with weak green (525 nm) and strong (438 nm) and weak (475 nm) blue peaks. DFT-LDA + U calculations exhibits an antiferromagnetic phase with slightly reduced Eg (3.379 eV for x = 0 % and 3.267 for 3.7 %), attributed to the influence of Mn3d states near the Fermi level. This study presents a comprehensive analysis of low-content Mn-doped ZnO thin films by combining experimental and theoretical approaches. The findings provide valuable insights into the electronic, structural, optical, and magnetic properties of MZO, emphasizing the critical role of Mn 3d states in altering the magnetic behavior and adjusting Eg.

Citation

Bahri DEGHFEL , , (2025-02-01), Synthesis of low-content Mn-doped ZnO thin films: Characterizations and density functional theory studies, Inorganic Chemistry Communications, Vol:172, Issue:1, pages:113710, Elsevier B.V.

This study aims to prepare manganese-doped zinc oxide (MZO) thin films with low Mn content (x = 0, 2, 4 %) using the sol–gel spin coating method and to characterize their structural, optical, and magnetic properties. Experimental techniques were complemented by Density Functional Theory calculations with Hubbard correction (DFT-LDA + U). All films exhibit a polycrystalline wurtzite hexagonal phase of ZnO. As the Mn doping increases, all diffraction peaks are getting weaker, which leads to deterioration in the crystallinity of the samples. Furthermore, Mn doping affects the grain size (57.44–38.20 nm), the surface morphology (rms: 45.24–30.47 nm), the transmittance (93–54 %) and the optical band gap energy (Eg: 3.27–3.18 eV). Photoluminescence spectra reveals ultraviolet peaks (386–395 nm) along with weak green (525 nm) and strong (438 nm) and weak (475 nm) blue peaks. DFT-LDA + U calculations exhibits an antiferromagnetic phase with slightly reduced Eg (3.379 eV for x = 0 % and 3.267 for 3.7 %), attributed to the influence of Mn3d states near the Fermi level. This study presents a comprehensive analysis of low-content Mn-doped ZnO thin films by combining experimental and theoretical approaches. The findings provide valuable insights into the electronic, structural, optical, and magnetic properties of MZO, emphasizing the critical role of Mn 3d states in altering the magnetic behavior and adjusting Eg.

Citation

ELHADJ Benrezgua , Rabie AMARI , AMMAR Boukhari , Djamel ALLALI , Smail TERCHI , Bahri DEGHFEL , ABDELHAMID Guelil , Abdelhalim Zoukel, Ahmad Azmin Mohamad, , (2025-02-01), Synthesis of low-content Mn-doped ZnO thin films: Characterizations and density functional theory studies, Inorganic Chemistry Communications, Vol:172, Issue:172, pages:113710, Elsevier, Science Direct

Using the full-potential linearised augmented plane wave approach, we examined the structural, electronic, and optical features of AgXBr3 perovskite materials (X = Ca, Sr, or Ba). The GGA-PBEsol exchange-correlation functional yields equilibrium structure parameters that match the literature. Electronic structure analysis demonstrates that the Tran–Blaha modified Becke–Johnson and screened hybrid HSE06 functionals widen the bandgap compared to GGA-PBEsol. As X’s atomic size rises, its indirect fundamental bandgap lowers. The density of states diagrams, complex dielectric function, electronic energy loss function, absorption coefficient, reflectivity, extinction coefficient, and refractive index were thoroughly explored. Results show that reducing the bandgap increases the dielectric function’s zero frequency limits. Origins of optical spectra peaks and characteristics have been identified.

Citation

Bahri DEGHFEL , , (2025-01-07), Investigation of the structural, electronic and optical properties of halide perovskites AgXBr3 (X = Ca, Sr, and Ba) using DFT framework, Indian Journal of Physics, Vol:99, Issue:8, pages:11123, Springer Nature

This study investigates the effect of incorporating gold nanoparticles (Au NPs) into the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) active layer of organic solar cells (OSCs). GPVDM simulation software was used to analyze the power conversion efficiency (PCE) along with other photovoltaic properties, including open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF), in both conventional and inverted architectures. The addition of a 5% concentration of Au NPs led to a significant increase in PCE, with a maximum value of 6.46% in specific buffer layer configurations, compared to 4.65% in devices without Au NPs. The effect of varying hole blocking layer (HBL) materials, such as BPhen, ZnO, and TiOx, was also examined, revealing improvements in device performance, with BPhen achieving the highest efficiency among the tested materials.

Citation

Bahri DEGHFEL , , (2025-01-03), Gold nanoparticles in P3HT: PCBM active layer: A simulation of new organic solar cell designs, Solid-State Electronics, Vol:225, Issue:1, pages:109056, Elsevier Ltd

Small-molecule organics have significant potential to revolutionize solar energy conversion due to their efficiency and cost-effectiveness. This study presents three novel tetrathiafulvalene-based organic donors: TTF-COOH, TTF-CS, and TTF-MCS. We successfully synthesized and characterized these compounds using Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), and UV–Vis spectroscopy. They exhibit good optical properties, with strong absorption peaks at 554 nm for TTF-COOH, 370 nm for TTF-MCS, and 384 nm for TTF-CS. Density Functional Theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to analyze frontier molecular orbitals, global reactivity parameters, molecular electrostatic potential, electron excitation properties, transition density matrices, and photovoltaic properties. The results reveal low band gaps (3.04–4.14 eV) and low exciton binding energies (0.79–0.92 eV), indicating efficient electron transfer and faster exciton dissociation. Additionally, the compounds display high open-circuit voltages (1.34–2.08 V) and fill factors (90.6 %–93.4 %), making them promising candidates for organic solar cell applications.

Citation

Bahri DEGHFEL , , (2024-12-04), Innovative Tetrathiafulvalene (TTF)-Based Organic Donors for Solar Cells: Synthesis, Characterization, and DFT Analysis, Journal of Molecular Structure, Vol:1325, Issue:1, pages:141022, Elsevier B.V.

This work highlights the significant potential of Manganese-doped Zinc Oxide (Mn-doped ZnO) nanoparticles in enhancing supercapacitor electrodes, sparking extensive research interest. The hydrothermal synthesis method has gained prominence for fabricating Mn-doped ZnO nanoparticles. While the impact of Mn doping on other nanomaterials has been well-studied, the remains a gap in comprehensive research focused on Mn-doped ZnO nanoparticles for supercapacitors. This review addresses this gap by compiling and comparing existing research on the applications of Mn-doped ZnO in supercapacitors. Through a detailed analysis of past studies, this paper explains the distinct advantages of Mn-doped ZnO in supercapacitor applications and identifies areas for further improvement. It offers a thorough summary of the physical and electrochemical characteristics critical to supercapacitor performance, such as cyclic voltammetry, constant current charge–discharge, structure, morphology, and elemental analysis. Additionally, the review provides an in-depth discussion on how Mn doping specifically influences these performance aspects, making a significant contribution to advancing the understanding and development of superior supercapacitor technologies.

Citation

Bahri DEGHFEL , , (2024-12-01), Hydrothermal synthesis of manganese doped zinc oxide wurtzite nanoparticles for supercapacitors–A brief review, Inorganic Chemistry Communications, Vol:170, Issue:2, pages:113311, Elsevier B.V.

Water pollution is a major global challenge, causing severe repercussions for both the environment and human health. Adsorption using bio-adsorbents is a promising method for removing these pollutants. This study focuses on the valorization of date peels, an agricultural waste, by developing activated carbon from these residues. The activated carbon was characterized by zero charge point (pH_pzc) measurements and Fourier transform infrared spectroscopy (FTIR) analysis. A series of experiments was conducted to evaluate he impact of contact time, pH, dosage, and temperature on adsorption capacity and process kinetics. The integration of nanometric materials into the design of these bio-adsorbents could enhance their efficiency and broaden their applications in wastewater treatment. The exploration of these new adsorbents, which are sustainable, economical, and easily accessible, is a priority for researchers seeking innovative solutions in this field.

Citation

Lamya MEFTAH , Smail TERCHI , Bahri DEGHFEL , ELHADJ Benrezgua , ,(2024-10-31), valorization of Agricultural Waste: Development of Bio Adsorbents from Date Peels for Wastewater Treatment,r'1 INTERNATIONAL CONFERENCE ON TECHNOLOGICAL APPLICATIOl\ OF MA ERIALS (ICTAM'24),Sétif

Mn doped ZnO thin films (MZO) with varying doping levels (x) were prepared using the sol-gel spin coating method. All films exhibited a stable hexagonal polycrystalline wurtzite phase after doping. The surface morphology was slightly altered, with a decrease in grain size [1]. The transmittance of the films reduced, and the optical band gap energy (Eg) showed a slight decrease as Mn doping increased [2]. Additionally, the transparency of the films diminished due to oxygen vacancies and increased grain boundary density. The UV absorption edge shifted to longer wavelengths with higher Mn content, further reducing the band gap energy.

Citation

Bahri DEGHFEL , ,(2024-10-30), Mn doped ZnO films: A comparative structural and optical properties study.,1st International Conference on Technological Application of Materials (ICTAM'24),Sétif, Algéria

La pollution des eaux est l'un des problèmes les plus répandus à l'échelle mondiale, entraînant des conséquences néfastes pour l'environnement et la santé humaine. L'adsorption par des bio-adsorbants représente l'une des méthodes les plus efficaces pour éliminer ces polluants. Ce travail vise à valoriser les déchets agricoles, notamment les pelures d'amandes, en développant un charbon actif à partir de ces résidus. Notre adsorbant a été caractérisé à l'aide de mesures du point de charge nulle (pH_pzc) et d'une analyse par spectroscopie infrarouge à transformée de Fourier (IRTF). Une série d'expériences a été conduite afin d'étudier l'impact du temps de contact, du pH, de la dose et de la température sur la capacité d'adsorption ainsi que sur la cinétique du processus. L'exploration de nouveaux adsorbants, naturellement abondants, faciles à collecter, économiques et disponibles en permanence, constitue un objectif majeur pour de nombreux chercheurs dans ce domaine.

Citation

Lamya MEFTAH , Smail TERCHI , Bahri DEGHFEL , ELHADJ Benrezgua , ,(2024-10-14), Valorisation des pelures d'amandes en charbon actif pour l'épuration des eaux usées : Caractérisation et étude des capacités adsorbantes,1er Séminaire National : Eau, Environnement et Energies Renouvelables (SN3ER’2024),M'sila

The main objective of this study is to obtain three-dimensional empirical K-shell x-ray fluorescence cross-section and values for a wide range of elements for photons with energies from 5.46 keV to 123.6 keV, using more than 3300 experimental data values published between 1985 and 2023 by numerous researchers. These data values are fitted using an interpolation method including a three-dimensional function against atomic number Z and excitation energy E, resulting in a three-dimensional plot to estimate empirically a three-dimensional set of and x-ray fluorescence cross sections. The results of this empirical calculation are compared, for selected elements, with other empirical and experimental values reported in the literature, and a reasonable agreement is observed.

Citation

Bahri DEGHFEL , , (2024-09-04), Empirical calculation of K-shell fluorescence cross sections for elements in the atomic range 16≤ Z≤ 92 by photon effects ranging from 5.46 to 123.6 keV (Three-dimensional formulae), Physica Scripta, Vol:99, Issue:10, pages:105402, IOP Publishing

Les oxydes métalliques, sous forme de poudres nanostructurées et de couches minces, jouent un rôle crucial dans de nombreux domaines grâce à leurs propriétés physico-chimiques uniques. Cette conférence explore les approches avancées pour leur élaboration, incluant les méthodes chimiques (sol-gel, hydrothermale, électrodéposition) et physiques (pulvérisation cathodique, dépôt par faisceau laser, évaporation thermique). L’accent sera mis sur les techniques de caractérisation modernes, telles que la microscopie électronique à balayage (SEM), la diffraction des rayons X (XRD) et la spectroscopie UV-Vis, pour évaluer la structure, la composition et les propriétés fonctionnelles des matériaux produits. En termes d’applications, la conférence mettra en évidence l’efficacité des oxydes métalliques dans le traitement des eaux usées, en se concentrant sur la photocatalyse et l’adsorption. Les exemples incluront des études sur la dégradation des composés organiques persistants et l’amélioration des paramètres tels que la demande chimique en oxygène (DCO). L’objectif de cette conférence est de démontrer le potentiel des oxydes métalliques élaborés par des méthodes avancées en tant que solutions durables pour relever les défis environnementaux liés à la gestion des eaux usées.

Citation

Bahri DEGHFEL , ,(2024-06-13), Oxydes en Poudre et Couches Minces : Élaboration, Caractérisation et Application,1ère Journée de Formation et Portes Ouvertes,المسيلة

Nickel oxide (NiO) nanoparticles were synthesized at different pH levels via a sol–gel method and calcined using microwave assistance. The study explored the effects of pH on NiO nanoparticles morphology, structure and electronic properties. Density functional theory (DFT + U) calculations were employed to investigate the structural and electronic properties of the material. NiO synthesized at pH 8 displayed superior crystallinity and particle size distribution, with spherical-like nanoparticles averaging 3 nm in size. DFT + U calculations revealed a band gap of 4.07 eV and a surface energy convergence of 51 meV/Å2, indicating stability. These findings suggest pH 8 as the optimal condition for NiO synthesis. Electrochemical tests demonstrated a high specific capacitance of 87.7F g−1 at a scan rate of 10 mV s−1, indicating promising electrochemical properties for supercapacitor applications.

Citation

Bahri DEGHFEL , , (2024-06-01), Microwave Assisted Synthesis of Nickel Oxide Nanoparticles at Different Ph Via Sol Gel Method: Experimental and First-Principles Investigations, Inorganic Chemistry Communications, Vol:164, Issue:, pages:112415, Elsevier B.V.

Dans cette étude, nous avons utilisé la vermiculite sodique comme adsorbant d’un colorant azoique. Le polluant étudié c’est l’acide rouge ; plusieurs paramètres d’adsorption telle que le pH de la solution, temps de contact, dose d’adsorbant, concentration initiale du colorant, la salinité ont été étudiés. Les résultats de cette étude montre que le milieu acide est favorise mieux l’adsorption du colorant. L’étude cinétique montre que l’adsorption est rapide ou se déroule ou bout d’une heure le système adsorbant-colorant atteint à l’équilibre. La dose optimale d’adsorbant est de 0,05g dans 50 ml de solution. D’après les modélisations de isotherme d’adsorption le modèle Freundlich est le plus approprié. Ces résultats sont comparés avec une matériau hybride; St/argile . L’étude cinétique montre que l’adsorption est rapide ou se déroule ou bout d’une heure le système adsorbant-colorant atteint à l’équilibre. La dose optimale d’adsorbant est de 0,05g dans 25 ml de solution. D’après les modélisations de isotherme d’adsorption le modèle Freundlich est le plus approprié.

Citation

Lamya MEFTAH , Smail TERCHI , Bahri DEGHFEL , ,(2024-05-22), Exploitation des propriétés adsorbantes de la vermiculite dans le domaine traitement des eaux,Journée Doctorale surle TraitementElectrochimiquedes EauxPolluées,M'sila

Dans cette étude, nous avons utilisé la vermiculite sodique comme adsorbant d’un colorant azoique. Le polluant étudié c’est l’acide rouge ; plusieurs paramètres d’adsorption telle que le pH de la solution, temps de contact, dose d’adsorbant, concentration initiale du colorant, la salinité ont été étudiés. Les résultats de cette étude montre que le milieu acide est favorise mieux l’adsorption du colorant. L’étude cinétique montre que l’adsorption est rapide ou se déroule ou bout d’une heure le système adsorbant-colorant atteint à l’équilibre. La dose optimale d’adsorbant est de 0,05g dans 50 ml de solution. D’après les modélisations de isotherme d’adsorption le modèle Freundlich est le plus approprié. Ces résultats sont comparés avec une matériau hybride; St/argile . L’étude cinétique montre que l’adsorption est rapide ou se déroule ou bout d’une heure le système adsorbant-colorant atteint à l’équilibre. La dose optimale d’adsorbant est de 0,05g dans 25 ml de solution. D’après les modélisations de isotherme d’adsorption le modèle Freundlich est le plus approprié.

Citation

Lamya MEFTAH , Smail TERCHI , Bahri DEGHFEL , Hamoudi Belhoul , ,(2024-05-06), Exploitation des propriétés adsorbantes de la vermiculite dans le domaine traitement des eaux,Le 2ème colloque national de chimie (CNC2@2024),M'sila

In this study, manganese oxide thin films were fabricated using the sol-gel spin coating method. Various protocols are available in the literature for the preparation of such films [1]. Our approach involved using manganese acetate tetrahydrate ((CH2COO)2Mn·4H2O) and monoethanolamine (MEA) (NH2CH2CH2OH) as precursors, with ethanol serving as the solvent. Initially, a specific quantity of Mn acetate tetrahydrate was dissolved in ethanol, followed by the addition of MEA in a 1:1 molar ratio with respect to Mn. The resulting solution was then stirred for 1.5 hours at 60°C. Subsequently, the solution was deposited onto a glass substrate using spin coating at a speed of 2000 rpm for 30 seconds, followed by calcination at 450°C. XRD analysis confirmed the presence of the α-MnO2 phase in our sample [2]. Furthermore, investigation of the optical properties revealed that the prepared manganese oxide films possess an indirect band gap of 2.24 eV.

Citation

Rabie AMARI , Bahri DEGHFEL , ,(2024-05-06), Study of Structural and Optical Properties of MnO2 thin films by Sol-gel spin coating Method,Le 2ème colloque national de chimie (CNC2@2024),Département de Chimie, Faculté des sciences,Université Mohamed Boudiaf - M’sila

First-principles calculations employing the density functional theory full-potential (linearized) augmented planewave plus local orbitals (FP-(L)/APW + lo) method were conducted to investigate the structural, electronic and optical characteristics of silver-based ternary oxides XAgO (X = Li, Na, K, and Rb). The GGA-PBEsol and TB-mBJ functionals were employed to describe the exchange-correlation potential. The optimized lattice parameters and atomic positions obtained from the calculations exhibit good agreement with both theoretical predictions and experimental measurements. Various exchange-correlation functionals were employed to evaluate the electronic properties, revealing that the newly developed Tran–Blaha modified Becke–Johnson functional yields a significant improvement in the band gap value. All XAgO compounds under consideration are categorized as semiconductor materials where the band gap value decreases as the atomic size of the X element increases. The study also explored the total and site-projected l-decomposed densities of states. Additionally, the complex dielectric function, refractive index, extinction coefficient, reflectivity, and loss function spectra were calculated for the incident radiation polarized parallel to both the [100] and [001] crystalline directions. The interband transitions that contribute effectively to the observed peaks in the imaginary part of the dielectric function were identified.

Citation

Bahri DEGHFEL , , (2024-03-01), A first-principles investigation on the structural, electronic and optical characteristics of tetragonal compounds XAgO (X= Li, Na, K, Rb), Computational Condensed Matter, Vol:38, Issue:12, pages:e00876, Elsevier B.V.

First-principles calculations employing the density functional theory full-potential (linearized) augmented planewave plus local orbitals (FP-(L)/APW + lo) method were conducted to investigate the structural, electronic and optical characteristics of silver-based ternary oxides XAgO (X = Li, Na, K, and Rb). The GGA-PBEsol and TB-mBJ functionals were employed to describe the exchange-correlation potential. The optimized lattice parameters and atomic positions obtained from the calculations exhibit good agreement with both theoretical predictions and experimental measurements. Various exchange-correlation functionals were employed to evaluate the electronic properties, revealing that the newly developed Tran–Blaha modified Becke–Johnson functional yields a significant improvement in the band gap value. All XAgO compounds under consideration are categorized as semiconductor materials where the band gap value decreases as the atomic size of the X element increases. The study also explored the total and site-projected l-decomposed densities of states. Additionally, the complex dielectric function, refractive index, extinction coefficient, reflectivity, and loss function spectra were calculated for the incident radiation polarized parallel to both the [100] and [001] crystalline directions. The interband transitions that contribute effectively to the observed peaks in the imaginary part of the dielectric function were identified.

Citation

Djamel ALLALI , SABER Saad Essaoud , Bahri DEGHFEL , Abdelmadjid Bouhemadou, , (2024-01-04), A first-principles investigation on the structural, electronic and optical characteristics of tetragonal compounds XAgO (X= Li, Na, K, Rb), Computational Condensed Matter, Vol:38, Issue:38, pages:e00876, Elsevier

ZnO and ZnO doped-Ag nanoparticles have been successfully produced using the coprecipitation method. Literature studies show that Ag doping into ZnO matrix can enhance its various properties [2, 3]. Zinc acetate dihydrate [Zn (CH3COO)2 2H2O], silver nitrate [AgNO3] and sodium hydroxide solution [NaOH] were used as precursors. To obtain homogeneous solution, stoichiometric amount of zinc and nickel acetate were dissolved in methanol and then stirred continuously on a magnetic stirrer at room temperature. To raise the pH of the obtained solution to ~9, a small amount of sodium hydroxide solution [NaOH] was added drop by drop. The obtained solution is then stirred again until the liquid solution turns into a gel. Then, the beaker was transferred on the hot plate at 500°C for 1h. The structural, morphological, electronic, optical and vibrational properties were examined. The analysis confirmed that all nanoparticles possessed a hexagonal wurtzite crystalline structure, with particle size being influenced by the presence of Ag. The particles exhibited a preference for orientation along the (002) axis. The shift in peak positions towards higher angles suggested that the Ag might replace Zn ions in the ZnO lattice. The surface structure of the nanoparticles displayed a combination of spherical and hexagonal shapes.

Citation

Bahri DEGHFEL , ,(2023-12-20), Study of Structural, Electronic and Optical Properties of Ag Doped ZnO Nanoparticles by Co-precipitation Method,1st National Conference on Matter Sciences,Djelfa, Algeria

Pure and Mn-doped zinc oxide thin films at contents x =10% were synthesized by sol–gel spin coating process and investigated using various techniques. both samples have wurtzite hexagonal phase, which wasn’t altered and getting relaxed by Mn-doping. The grain size decreased and did not change its growth mode in 10%Mn doping. at x= 10 %, the transparency of films was decreased in the visible region and the band gap energy (Eg) presented a slight shrinking. Photoluminescence spectra showed ultraviolet with strong and weak blue and weak green emission peaks. Keywords: Mn-doped ZnO, Thin films, Sol-gel technique, Spin coating method. References : 1. R. Amari, B. Deghfel, A. Mahroug, A.A. Mohamad, A. Boukhari, N. Selmi, Effects of Mn doping on the structural, morphological, electronic and optical properties of ZnO thin flms by sol-gel spin coating method: an experimental and DFT+U study, Phys. B Condens. Matter 577 (2020) 411766. 2. Benrezgua, E., Deghfel, B., Zoukel, A., Basirun, W. J., Amari, R., Boukhari, A., Yaakob, M. K., Kheawhom , S., & Mohamad, A. A. (2022). Synthesis and properties of copper doped zinc oxide thin films by sol-gel, spin coating and dipping: A characterization review. Journal of Molecular Structure, 1267, 133639. 3. A. Mahroug, R. Amari, A. Boukhari, B. Deghfel, L. Guerbous, N. Selmi, Synthesis, structural , morphological , electronic, optical and luminescence properties of pure and manganese-doped zinc oxide nanostructured thin flms: effect of doping .J. Nanoelectron. Optoelectron . 13 (2018) 732–742.

Citation

Bahri DEGHFEL , ,(2023-12-20), Structural, optical and photoluminescence Properties of ZnO pure and Mn-Doped ZnO Thin Films Grown by Sol-Gel Spin Coating Deposition,1st National Conference on Matter Sciences,Djelfa, Algeria

Electronic and optical properties of of AgBaBr3 Perovskites has been calculated using an ab initio study with the Tran-Blaha- modified Becke-Johnson density functional. the obtained results have been compared with available theoretical and experimental results. A good agreement has been found.

Citation

Bahri DEGHFEL , ,(2023-12-02), Electronic and optical properties of of AgBaBr3 Perovskites: An ab initio study with the Tran-Blaha- modified Becke-Johnson density functional,1st National Conference on Physics and its Applications,Bousaada, Algeria

Structural and electronic properties of AgBeC13 Perovskites: DFT based First-principles calculations

Citation

Bahri DEGHFEL , ,(2023-12-02), Structural and electronic properties of AgBeC13 Perovskites: DFT based First-principles calculations,1st National Conference on Physics and its Applications,Bousaada, Algeria

In this work, the Cambridge Serial Total Energy Package CASTEP within Density Functional Theory (DFT) is used to study the structural and electronic properties of cubic silver based perovskite AgXCl3 (X= Be; space group pm-3m (221)). The structural investigation reveals the stability of these compounds. The band structure and density of states indicates the semiconducting nature of the compound.The study reveals the potential as candidates for optoelectronic devices.

Citation

AMMAR Boukhari , Rabie AMARI , Djamel ALLALI , Bahri DEGHFEL , ,(2023-12-02), Structural and electronic properties of AgBeCl3 Perovskites: DFT based First-principles calculations,THE 1ST NATIONAL CONFERENCE ON PHYSICS AND IT’S APPLICATIONS,BOUSAADA

The present research utilizes ab initio computations to examine the thermodynamic, structural, and elastic characteristics of XAgO ternary oxides, where X signifies Li, Na, K, and Rb.The GGA-PBE and GGA-WC functionals were used to calculate the ground-state lattice parameters and atomic position coordinates of the title materials. The calculated results were in good agreement with both experimental measurements and theoretical predictions. This suggests that the GGA-PBE and GGA-WC functionals are accurate for describing the structural properties of the material under study.This study offers computational predictions for the elastic properties of monocrystalline structures and polycrystalline aggregates of XAgO compounds. These predictions encompass various key parameters, including single-crystal elastic constants, Young's modulus, bulk modulus, Lame coefficients, Poisson's ratio, shear modulus, and Debye temperature. Additionally, the quasi-harmonic Debye approximation is utilized to explore the temperature-dependent behavior of bulk modulus, Debye temperature, volume thermal expansion coefficient, and isobaric and isochoric heat capacities over an extensive temperature range, while maintaining constant pressures. The results obtained from this model are found to be highly successful in accurately predicting the behavior of these properties.

Citation

Djamel ALLALI , Rabie AMARI , AMMAR Boukhari , Bahri DEGHFEL , SABER Saad Essaoud , Abdelmadjid Bouhemadou, Saad Bin-Omran, Missoum Radjai, Rabah Khenata, Yarub Al-Douri, , (2023-10-04), Ab initio investigation of structural, elastic, and thermodynamic characteristics of tetragonal XAgO compounds (X = Li, Na, K, Rb), Physica Scripta, Vol:98, Issue:11, pages:115905, IOPscience

The present research utilizes ab initio computations to examine the thermodynamic, structural, and elastic characteristics of XAgO ternary oxides, where X signifies Li, Na, K, and Rb.The GGA-PBE and GGA-WCfunctionals were used to calculate the ground-state lattice parameters and atomic position coordinates of the title materials. The calculated results were in good agreement with both experimental measurements and theoretical predictions. This suggests that the GGA-PBE and GGAWCfunctionals are accurate for describing the structural properties of the material under study.This study offers computational predictions for the elastic properties of monocrystalline structures and polycrystalline aggregates of XAgO compounds. These predictions encompass various key parameters, including single-crystal elastic constants, Young’s modulus, bulk modulus, Lame coefficients, Poisson’s ratio, shear modulus, and Debye temperature. Additionally, the quasi-harmonic Debye approximation is utilized to explore the temperature-dependent behavior of bulk modulus, Debye temperature, volume thermal expansion coefficient, and isobaric and isochoric heat capacities over an extensive temperature range, while maintaining constant pressures. The results obtained from this model are found to be highly successful in accurately predicting the behavior of these properties.

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Djamel ALLALI , AMMAR Boukhari , Rabie AMARI , Bahri DEGHFEL , SABER Saad Essaoud , Bouhemadou Abdelmadjid, , (2023-10-04), Ab initio investigation of structural, elastic, and thermodynamic characteristics of tetragonal XAgO compounds (X = Li, Na, K, Rb), Physica scripta, Vol:98, Issue:, pages:115905, IOPscience

In the present study, transition metal Al-doped ZnO nanoparticles (TM-ZN NPs) were synthesized via the chemical co-precipitation method. The structural, morphological, electronic, optical, vibrational as well as the photocatalytic properties of the elaborated TMZO-NPs, are then investigated. Hexagonal wurtzite crystallinity of all elaborated NPs is confirmed by the phase analysis and particle size is found to be affected by TM doping. XRD peak shows that all samples prefer orientation along (002) axis and TM (Al) may substitute ZnO structure as the peaks shift toward higher angles. The surface morphology of all samples exhibits mixture of spheroid-like and hexagon-like shaped structures. FTIR analyses are carried out to identify the important bands attributed to TM-O and Zn-O stretching vibration modes. The absorption intensity and edge are found affected by adding TM dopant. Degradation by pure ZnO and TMZO NPs of the methylene blue is investigated after 90 min UV light exposure. TM dopant affects the degradation of MB dye, where a high percentage (97.14%) being achieved after reasonable time of exposure (90 min) under UV light for Aluminum doped ZnO nanoparticles (AlZO NPs).

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Rabie AMARI , ELHADJ Benrezgua , Bahri DEGHFEL , AMMAR Boukhari , Djamel ALLALI , Siassi A, ,(2023-08-16), Studies on photocatalytic performance applications of undoped and Al-doped ZnO nanoparticles,NANO-2023,Bukovel, UKRAINE

In this study, we conducted an ab initio investigation of the structural, electronic and optical properties of AgCaBr3 and AgSrBr3 Calcium-based halide perovskites. using the full-potential linearized augmented plane-wave (FP-LAPW+lo) method [1] basis set as implemented in the WIEN2k code [2].Calculated structural parameters, including the lattice constants (a), bulk modulus (B) and its pressure derivative (B'), for the considered compounds using both the local density (LDA) [3] and generalized gradient approximations (GGA–PBEsol) [4] are consistent with the available data in the scientific literature. To calculate the electronic properties, the exchange-correlation potential is treated with various functionals, and we find that the newly developed Tran–Blaha-modified Becke–Johnson (TB-mBJ) [5–7] functional significantly improves the band gap. Band structure, total and site-projected l-decomposed densities of states, charge-carrier effective masses, charge transfers and charge density distribution maps were obtained; analyzed and compared with the available theoretical data. The frequency-dependent complex dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity and electron energy loss function spectra were calculated. The origins of the peaks and structures in the optical spectra are determined in terms of the calculated energy band structures.

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Djamel ALLALI , Rabie AMARI , Bahri DEGHFEL , AMMAR Boukhari , ,(2023-08-16), Electronic and optical properties of of AgXBr3 (X = Ca and Sr) Perovskites: An ab initio study with the Tran–Blaha-modified Becke–Johnson density functional,NANO-2023,Bukovel, UKRAINE

In this study, we conducted an ab initio investigation of the structural, electronic and optical properties of AgCaBr3 and AgSrBr3 Calcium-based halide perovskites. using the full-potential linearized augmented plane-wave (FP-LAPW+lo) method [1] basis set as implemented in the WIEN2k code [2].Calculated structural parameters, including the lattice constants (a), bulk modulus (B) and its pressure derivative (B'), for the considered compounds using both the local density (LDA) [3] and generalized gradient approximations (GGA–PBEsol) [4] are consistent with the available data in the scientific literature. To calculate the electronic properties, the exchange-correlation potential is treated with various functionals, and we find that the newly developed Tran–Blaha-modified Becke–Johnson (TB-mBJ) [5–7] functional significantly improves the band gap. Band structure, total and site-projected l-decomposed densities of states, charge-carrier effective masses, charge transfers and charge density distribution maps were obtained; analyzed and compared with the available theoretical data. The frequency-dependent complex dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity and electron energy loss function spectra were calculated. The origins of the peaks and structures in the optical spectra are determined in terms of the calculated energy band structures. 1. Cottenier S. Density Functional Theory and the Family of (L)APW-methods: aStep-bystep Introduction // Instituut voor Kern-en Straling sfysica, KU Leuven, Belgium 4,second ed., ISBN-2002-2013.-978-90.- P. 807215-807222. 2. Blaha P., Schwarz K., Madsen G., Kvasnicka D., Luitz J. WIEN2k:An Augmented Plane Wave Plus Local Orbitals Program for Calculating Crystal Properties // Vienna University of Technology, Institute of Materials Chemistry Getreidemarkt, Vienna, Austria-2017.- 9/165-TC A-1060. 3. Perdew J.P., Wang Y. Accurate and simple analytic representation of the electron-gas correlation energy // Phys. Rev. B-1992.-45.- P. 13244-13249. 4. Perdew J.P., Ruzsinszky A., Csonka G.I., Vydrov O.A., Scuseria G.E., Constantin L.A., Zhou X., Burke, K. Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces // Phys. Rev. Lett.-2008.-100.- P. 136406-136410.

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Bahri DEGHFEL , ,(2023-08-16), Electronic and optical properties of of AgXBr3 (X = Ca and Sr) Perovskites: An ab initio study with the Tran–Blaha-modified Becke–Johnson density functional,11th International Conference “Nanotechnologies and Nanomaterials” (NANO-2022),Ukraine

AN AB INITIO STUDY OF THE STRUCTURAL, ELASTIC, ELECTRONIC AND OPTICAL PROPERTIES OF AgCaX3 (X = Br, and F) PEROVSKITES have been claculated using DFT. The obtained results have been compared with available experimental and theoretical results. A good agreement is obtained.

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Bahri DEGHFEL , ,(2023-06-15), AN AB INITIO STUDY OF THE STRUCTURAL, ELASTIC, ELECTRONIC AND OPTICAL PROPERTIES OF AgCaX3 (X = Br, and F) PEROVSKITES,4th INTERNATIONAL MEDITERRANEAN CONGRESS,Nicosia-Cyprus, Turkey

The study successfully produced ZnO and ZnO nanoparticles doped with transition metals (TMZO-NPs) using the coprecipitation method. Various properties of these nanoparticles were examined, including their structure, morphology, electronic behavior, optical characteristics, vibrations, and photocatalytic abilities. The analysis confirmed that all nanoparticles possessed a hexagonal wurtzite crystalline structure, with particle size being influenced by the presence of transition metals (Al, Ag, Cu, Mn). The particles exhibited a preference for orientation along the (002) axis. The shift in peak positions towards higher angles suggested that the TM might replace Zn ions in the ZnO lattice. The surface structure of the nanoparticles displayed a combination of spherical and hexagonal shapes. Further analysis identified important bands related to the stretching modes of TM-O and Zn–O bonds. The absorption properties and edges were also affected by the presence of TM. In the degradation study, both pure ZnO and TMZO-NPs were tested for their ability to break down methylene blue (MB) under UV light exposure for 90 min. Among the nanoparticles, Al-doped ZnO (AlZO-NPs) demonstrated the highest degradation efficiency, achieving 97.14% removal of MB within the given exposure time. The photocatalytic process followed a pseudo-first-order kinetics, indicating a strong correlation. This suggests that AlZO-NPs hold promise as a material for use in photocatalytic applications.

Citation

Bahri DEGHFEL , , (2023), Coprecipitation synthesis of transition metal (Al, Mn, Cu, Ag) doped zinc oxide nanopowders: characterization, photocatalytic test, and comparison study, Journal of the Australian Ceramic Society, Vol:11, Issue:, pages:7, Springer Link

The structural, elastic, electronic, and magnetic properties of the CrCoSi, MnCoSi parent half-Heusler (HH) alloys, and their CrMnCo2Si2 derivative double half-Heusler (DHH) compound are studied, utilizing the augmented plane wave method, which is based on density functional theory and implemented in the WIEN2k code. The stability of HH structure of the CrCoSi and MnCoSi alloys has been checked for their non-magnetic and ferromagnetic phases, leading to that the latter phase of the type I arrangement is the most stable. The CrMnCo2Si2 DHH alloy, derivative from the found structural and magnetic ground states of CrCoSi and MnCoSi HH alloys, is constructed and investigated. This DDH as well as its CrCoSi parent HH are found to be resistant to deformation and can be classified as ductile materials, whereas the MnCoSi compound is brittle. By the gradient generalized approximation (GGA), the electronic structures of CrCoSi, MnCoSi, and CrMnCo2Si2compounds exhibit a metallic behavior in the spin-up channel and a semiconducting behavior in the spin-dn channel, with band gaps (half-metallic gaps) of 0.851(0.020), 0.852(0.021), and 0.531(0.002) eV, respectively. The half-metallicity of CrMnCo2Si2 DHH is retained with smaller (larger) band gap (half-metallic gap) of 0.38(0.106) eV than that of GGA, using GGA + U approximation. In addition, the total magnetic moments are found to be 1, 2, and 3 μB for CrCoSi, MnCoSi, and CrMnCo2Si2, respectively. Therefore, these alloys can be good candidates for spinitronic applications due to their half-metallicity.

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Bahri DEGHFEL , , (2023), Half-metallicity from CrCoSi and MnCoSi half-Heusler alloys to their derivative double half-Heusler CrMnCo2Si2, Canadian Journal of Physics, Vol:10, Issue:112, pages:1-8, Canadian Science Publishing

The present research utilizes ab initio computations to examine the thermodynamic, structural, and elastic characteristics of XAgO ternary oxides, where X signifies Li, Na, K, and Rb.The GGA-PBE and GGA-WC functionals were used to calculate the ground-state lattice parameters and atomic position coordinates of the title materials. The calculated results were in good agreement with both experimental measurements and theoretical predictions. This suggests that the GGA-PBE and GGAWC functionals are accurate for describing the structural properties of the material under study.This study offers computational predictions for the elastic properties of monocrystalline structures and polycrystalline aggregates of XAgO compounds. These predictions encompass various key parameters, including single-crystal elastic constants, Young’s modulus, bulk modulus, Lame coefficients, Poisson’s ratio, shear modulus, and Debye temperature. Additionally, the quasi-harmonic Debye approximation is utilized to explore the temperature-dependent behavior of bulk modulus, Debye temperature, volume thermal expansion coefficient, and isobaric and isochoric heat capacities over an extensive temperature range, while maintaining constant pressures. The results obtained from this model are found to be highly successful in accurately predicting the behavior of these properties.

Citation

Bahri DEGHFEL , , (2023), Ab Initio Investigation of Structural, Elastic, and Thermodynamic Characteristics of Tetragonal XAgO Compounds (X= Li, Na, K, Rb)., Physica Scripta, Vol:98, Issue:10, pages:115905, IOP Publishing

Ab initio full-potential (linearized) augmented plane-wave plus local orbitals (FP-(L)APW + lo) calculations are performed to study the hydrostatic pressure dependence of the mechanical and thermodynamics properties of GeMg2O4, GeZn2O4, and GeCd2O4 cubic spinels. The calculated equilibrium structural parameters using both the local density approximation and the generalized gradient approximation are well consistent with the available theoretical and experimental data in the literature. The monocrystalline elastic constants are predictet using the energy-strain scheme. The polycrystalline elastic moduli are determined from the monocrystalline elastic constants through the Voigt-Reuss-Hill approximations. To understand the mechanical behavior of the investigated compounds, assessments of their mechanical stability, ductility/brittleness, sound velocities, elastic anisotropy, pressure-dependent elastic constants, and Debye temperature are made. Regarding thermodynamic properties, temperature dependence of the lattice parameter, bulk modulus, isochoric and isobaric heat capacities, volume thermal expansion coefficient, and Debye temperature at different fixed pressures are explored through the quasi-harmonic Debye model coupled with the FP-(L)APW + lo approach.

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Djamel ALLALI , Bahri DEGHFEL , fares.zerarga@univ-bejaia.dz, abdelmadjid.bouhemadou@univ-setif.dz, , (2022), Ab initio study of the pressure dependence of mechanical and thermodynamic properties of GeB2O4 (B= Mg, Zn and Cd) spinel crystals, Computational Condensed Matter, Vol:32, Issue:, pages:e00705, Elsevier B.V.

The aim of this contribution is to investigate the different empirical procedures to deduce the L lines x-ray production cross sections for a wide range of elements (50≤Z ≤ 92) by proton impact. The data base which relies on different compilations available in the literature, is used from three different aspects, to deduce a new empirical production cross sections of the main x-ray lines Lα, Lβ and Lγ. One, the data are fitted collectively by analytical functions to calculate the empirical cross sections. Second, three dimensional empirical L-shell x-ray production cross sections have been deduced by introducing the dependence of the universal trend of the updated experimental data on the atomic number of the target, noted as “Z-dependence”. Third, these experimental data can be presented in a single curve depending on a scaling law extracted from studies in the most familiar theories of collision (PWBA). Then, a first order exponential decay function was used to fit very well the existing database of the main x-ray lines Lα, Lβ and Lγ cross sections for elements from 50Sn to 90U. Generally, the deduced production cross sections obtained by fitting the available experimental data for each element separately give the most reliable values than those obtained by a global fit. At last, a comparison is made between the three empirical formula reported in this work, those obtained using the ECPSSR model and other earlier works.

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Bahri DEGHFEL , , (2022), Universal empirical fit to Lα, Lβ and Lγ x-ray production cross section by protons impact within updated experimental data: Three dimensional (Z-dependence), collective and individual formulae, Radiation Physics and Chemistry, Vol:190, Issue:, pages:109823, Elsevier Ltd.

Zn0.875Al0.125O nanoparticles are fabricated by a co-precipitation technique using zinc acetate dehydrate [Zn(CH3COO)2•2H2O] and aluminum nitrate nonahydrate(Al(NO3)39(H2O) as a starting material and doping source. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of Al doping on the structural, electronic and optical properties of ZnO nanoparticles. The obtained results are compared with those using first-principles calculation based on density functional theory (DFT) with local density approximation (LDA) plus Hubbard U (DFT–LDA+U) method. This latter represents the theoretical framework to deal with strongly correlated materials to predicted successfully the electronic properties of such materials. Keywords: Coprecipitation technique; Al-doped ZnO nanoparticles; DFT.

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Bahri DEGHFEL , ,(2022), Theoretical and experimental study of structural, electronic and optical properties of Al doped ZnO nanoparticles by co-precipitation method,10th International Conference on Materials Sciences And Technology, (MatScience-2022),khenchela, Algeria

Zn0.875Al0.125O nanoparticles are fabricated by a co-precipitation technique using zinc acetate dehydrate [Zn(CH3COO)2•2H2O] and aluminum nitrate nonahydrate(Al(NO3)39(H2O) as a starting material and doping source. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of Al doping on the structural, electronic and optical properties of ZnO nanoparticles. The obtained results are compared with those using first-principles calculation based on density functional theory (DFT) with local density approximation (LDA) plus Hubbard U (DFT–LDA+U) method. This latter represents the theoretical framework to deal with strongly correlated materials to predicted successfully the electronic properties of such materials.

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Djamel ALLALI , Rabie AMARI , Bahri DEGHFEL , ,(2022), Electronic, structural, magnetic and optical properties of of spinel compound MgFe2O4,10th International Conference on Materials Sciences And Technology, (MatScience-2022),khenchela, Algeria

Structural parameters, elastic constants and thermodynamic properties of the tetragonal ternary Ag-based oxides LiAgO and NaAgO are investigated theoretically for the first time using the plane-wave ultra-soft pseudopotential method [1] based on the density functional theory [2,3]. The optimized lattice parameters and atomic positions agree well with the available theoretical and experimental counterparts. Pressure dependence of the structural parameters is also explored. Pressure dependences of the single-crystal elastic constants Cij for LiAgO and NaAgO are explored. The elastic wave velocities propagating along the principal crystallographic directions are numerically estimated. The elastic anisotropy is estimated and further illustrated by 3D-direction-dependent of the Young’s modulus. A set of some macroscopic elastic moduli, including the bulk, Young’s and shear moduli, Poisson’s coefficient, average elastic wave velocities and Debye temperature, were calculated for polycrystalline LiAgO and NaAgO from the Cij via the Voigt-Reuss-Hill approximations [4–6]. Through the quasiharmonic Debye model [7], which takes into account the phonon effects, the temperature and pressure dependencies of the bulk modulus, unit cell volume, volume thermal expansion coefficient, Debye temperature and volume constant and pressure constant heat capacities of LiAgO and NaAgO are explored systematically in the ranges of 0–20 GPa and 0–1200 K.

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Djamel ALLALI , Amari Rabie , Bahri DEGHFEL , AMMAR Boukhari , ,(2022), Structural, elastic and thermodynamic properties of Ag-based oxides XAgO (X = Li and Na): An ab initio study,10th International Conference “Nanotechnologies and Nanomaterials” (NANO-2022),Lviv. Ukraine

In this study, the thickness effect of 4% Mn-doped ZnO thin films on structural, optical, and morphological properties is investigated. The films are deposited on a glass substrate using the sol-gel spin coating method. Phase analysis indicates that all films have a hexagonal wurtzite structure with a high preferential c-axis orientation. All structural parameters are significantly influenced by the thickness variations. The optical analysis reveals that transmittance and band gap energy decrease with thickness. A red shift of the absorption edge is noticed. The surface morphology shows a good uniformity for all ZnO films. The surface roughness of the samples increases with film thicknesses. The photoluminescence (PL) spectra show a UV peak at 388 nm with two blue peaks at 438 and 475 nm and a weak green emission peak at 525 nm. A lower PL intensity is noticed by increasing the thickness. The obtained results exhibit similarities in behavior as other methods.

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AMMAR Boukhari , Bahri DEGHFEL , Abdelhafid MAHROUG , Rabie AMARI , Noureddine Selmi, Ahmad Azmin Mohamad, , (2021), Thickness Effect on the Properties of 4% Mn‐Doped ZnO Thin Films Grown by Sol‐Gel Spin Coating Deposition, Macromolecular Symposia, Vol:397, Issue:1, pages:2000235, Wiley Online Library

The current study investigates the effect of thickness on the structural, morphological, electronic, and optical properties of pure zinc oxide (ZnO) and 7% Mn-doped ZnO thin films, deposited by sol–gel spin coating method. All films exhibited a hexagonal wurtzite structure with a high preferential c-axis orientation. The surface morphology showed a good uniformity with cracks and wrinkles. The transmittance decreased with thickness. The bandgap energy was inversely varying with coating number. Photoluminescence spectra showed ultraviolet with strong and weak blue and weak green emission peaks. Density functional theory and Hubbard (DFT + U) method was then applied to study the structural, electronic, and optical properties of pure and 6.25% Mn-doped ZnO materials. A decrease in bandgap energy from pure to 6.25% Mn-doped ZnO material was shown using the DFT + U method. It also found that the Mn3d states were distributed far from Fermi level with a coexistence of both ionic and covalent nature bonds. A slight shift toward the lower energy was noticed for optical properties by Mn doping. The theoretical findings showed a similar behavior to those obtained by experiment.

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AMMAR Boukhari , Bahri DEGHFEL , Abdelhafid MAHROUG , Rabie AMARI , Noureddine Selmi, Soorathep Kheawhom, Ahmad Azmin Mohamad, , (2021), Thickness effect on the properties of Mn-doped ZnO thin films synthesis by sol-gel and comparison to first-principles calculations, Ceramics International, Vol:47, Issue:12, pages:17276-17285, Elsevier

Pure and copper-doped zinc oxide thin films at different contents x (Zn1-xCuxO; 0≤x ≤ 0.125) were synthesized by sol–gel spin coating process and investigated using various techniques. All samples exhibited a polycrystalline with wurtzite hexagonal phase, which wasn't altered and getting relaxed by Cu-doping. The grain size increased and changed its growth mode from c-axis growth to lateral one and the surface morphology was strongly influenced with increasing level of Cu doping. As x increased, the transparency of films was generally increased in the visible region and the band gap energy (Eg) presented a slight shrinking, indicating that the prepared films are suitable for use in opto-electronic applications. Ferromagnetic phase was adopted within density functional theory corrected by Hubbard method (DFT + LDA + U) to investigate the structural, electronic, magnetic and optical properties of pure and CZO structure. The closest Cu impurities gave the more stable configuration. Cu3d states were distributed around Fermi level inducing a major contribution to the magnetic moment. A mix of ionic and covalent bonding was remarked. DFT + LDA + U enhanced significantly the calculated Eg, which presented a narrowing with x. The imaginary part of the dielectric functions presented three main peaks and their static constants were slightly influenced by Cu doping.

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Bahri DEGHFEL , Abdelhafid MAHROUG , AMMAR Boukhari , Rabie AMARI , elhadj.benrezgua@univ-msila.dz, Muhamad Kamil Yaakob, Soorathep Kheawhom, Ahmad Azmin Mohamad, , (2021), Experimental and theoretical studies on structural, morphological, electronic, optical and magnetic properties of Zn1-xCuxO thin films (0≤ x≤ 0.125), Materials Science in Semiconductor Processing, Vol:134, Issue:, pages:106012, Elsevier

In this study,7% Mn-doped ZnO thin film was deposited on glass substrate using sol–gel spin coating method at 0,7 ZnO concentration, in order to investigate the structural, optical and morphological properties. XRD result exhibit that the deposited thin film has a hexagonal wurtzite structure with a preferential orientation along the (0 0 2) c-axis orientation. The grain size, lattice constants, FWHM and strain of the film were calculated. To characterize the electronic and optical properties, UV-Vis spectra were used. The results indicate that the average transmittance is 45.15% in the visible range. The optical band gap energy was found to be 2.577 eV. The surface morphology showed a good uniformity with few cracks and wrinkles.

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AMMAR Boukhari , Bahri DEGHFEL , Abdelhafid MAHROUG , Ahmad Azmin Mohammad, ,(2021), Structural, morphological and optical properties of Mn-doped ZnO thin films prepared by sol-gel spin coating method,1st international conference on materials and energies (IC- ME-21),Tamanghasset - Algeria

The structural, electronic and optical properties of Mn-doped ZnO thin films were studied using density functional theory (DFT) with Hubbard U method. Supercell model and substitutional method were employed to achieve the considered doping concentrations (x). Antiferromagnetic phase of Zn1−xMnxO (x = 0.125) structure was adopted at different geometry configurations. On the other hand, Zn1−xMnxO (x = 7, 10 and 12.5) thin films, with good uniformity, were fabricated using sol–gel spin coating technique. Both grain size and surface roughness were decreased with x, leading to the decrease of the average transmittance. Calculations revealed that Mn atoms tend to be close to each other around the O atom. Besides, Mn3d states were found to be rarely distributed around Fermi level. Furthermore, Mulliken analysis demonstrated the coexistence of both ionic and covalent bonding. Both materials presented a similar behavior for optical properties with a slight shift toward the lower energy by increasing x.

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Bahri DEGHFEL , , (2020), Effects of Mn doping on the structural, morphological, electronic and optical properties of ZnO thin films by sol-gel spin coating method: An experimental and DFT+U study, Physica B: Condensed Matter, Vol:577, Issue:15, pages:411766, ELSEVIER SCIENCE BV

This review aims to briefly outline the Hubbard-U scheme and to investigate the effect of its inclusion in standard Density Functional Theory on electronic, structural, and optical properties of ZnO wurtzite structure. To remedy the miscalculation of optimized lattice parameters determined by Local Density Approximation and Generalized Gradient Approximation approximations to experimental values, the effect of the implementation of Hubbard-U correction for only d state or for both d and p states was investigated for theoretical data collected from previous works. Further effort was devoted to studying the incorporation of Ud,Zn and Up,O to reproduce correct band gap, to exploring various regions composed of valence and conduction bands and their origin, and to revealing the nature of chemical bonding. This review also provides graphical and tabulated values extracted from earlier works on optical properties of ZnO wurtzite structure. It summarizes the effect of Ud,Zn and Up,O in several exchange–correlation functionals on the intensity and location of major peaks composed real and imaginary part of dielectric function as well as on the shift of main absorption peak and optical absorption edge. A comparison was made, wherever possible, between theoretical and experimental results.

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Bahri DEGHFEL , Kausar Harun, Nor Azmira Salleh, Muhamad Kamil Yaakob, Ahmad Azmin Mohamad, , (2020), DFT + U calculations for electronic, structural, and optical properties of ZnO wurtzite structure: A review, results in physics, Vol:16, Issue:, pages:102829, Elsevier B.V.

In this paper, a summary of existing experimental data published in the period of time between 1954 and 2015 is reviewed and presented in a tabular form for average L shell fluorescence yields taken from different sources. First, a critical examination of these data using the weighted average values is presented. Then, an interpolation using the well-known analytical function as a function of the atomic number Z is performed to deduce a new empirical average L shell fluorescence yields for elements in the range 23 ≤ Z ≤ 96. New theoretical calculations based on the configuration mixing Dirac-Fock method were performed for a few elements and are presented in this work. The results are compared with other theoretical, experimental and empirical values reported in the literature and a reasonable agreement has been obtained.

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Bahri DEGHFEL , Yassine Sahnoune, Abdelhalim Kahoul, , (2020), Updated database, new empirical and theoretical values of average L shell fluorescence yields of elements with 23≤Z≤96, Radiation Physics and Chemistry, Vol:166, Issue:, pages:108495, Elsevier Ltd

In this paper, we present a compilation of the measured photon-induced K/K intensity ratio values published in the literature from 1969 to 2018. In the considered period, we found about 1118 values (127 papers) for elements with . The analysis of the distribution of these experimental data values in function of the atomic number shows that almost all the elements from 11Na to 96Cm are covered, except some isolated cases with no data or less than two data values were found. It has been observed that the most exploited targets are in the region and and include an important number of data values. A critical examination of these data using weighted average values (K/K)w have been calculated for each element and recommended weighted values have been proposed.

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Bahri DEGHFEL , Salim Daoudi, Abdelhalim Kahoul, , (2020), Review of experimental photon-induced K/K intensity ratios, Atomic Data and Nuclear Data Tables, Vol:2, Issue:, pages:101308, Elsevier Inc

The structural, electronic and optical properties of Mn-doped ZnO thin films were studied using density functional theory (DFT) with Hubbard U method. Supercell model and substitutional method were employed to achieve the considered doping concentrations (x). Antiferromagnetic phase of Zn1−xMnxO (x = 0.125) structure was adopted at different geometry configurations. On the other hand, Zn1−xMnxO (x = 7, 10 and 12.5) thin films, with good uniformity, were fabricated using sol–gel spin coating technique. Both grain size and surface roughness were decreased with x, leading to the decrease of the average transmittance. Calculations revealed that Mn atoms tend to be close to each other around the O atom. Besides, Mn3d states were found to be rarely distributed around Fermi level. Furthermore, Mulliken analysis demonstrated the coexistence of both ionic and covalent bonding. Both materials presented a similar behavior for optical properties with a slight shift toward the lower energy by increasing x.

Citation

Rabie AMARI , Bahri DEGHFEL , Bahri DEGHFEL , , (2020), Effects of Mn doping on the structural, morphological, electronic and optical properties of ZnO thin films by sol-gel spin coating method: An experimental and DFT+U study, Physica B : Condensed Matter, Vol:577, Issue:19, pages:411766, Elsevier

The structural, electronic and optical properties of Mn-doped ZnO thin films were studied using density functional theory (DFT) with Hubbard U method. Supercell model and substitutional method were employed to achieve the considered doping concentrations (x). Antiferromagnetic phase of Zn1−xMnxO (x = 0.125) structure was adopted at different geometry configurations. On the other hand, Zn1−xMnxO (x = 7, 10 and 12.5) thin films, with good uniformity, were fabricated using sol–gel spin coating technique. Both grain size and surface roughness were decreased with x, leading to the decrease of the average transmittance. Calculations revealed that Mn atoms tend to be close to each other around the O atom. Besides, Mn3d states were found to be rarely distributed around Fermi level. Furthermore, Mulliken analysis demonstrated the coexistence of both ionic and covalent bonding. Both materials presented a similar behavior for optical properties with a slight shift toward the lower energy by increasing x.

Citation

Rabie AMARI , Bahri DEGHFEL , Bahri DEGHFEL , , (2020), Effects of Mn doping on the structural, morphological, electronic and optical properties of ZnO thin films by sol-gel spin coating method: An experimental and DFT+U study, Physica B : Condensed Matter, Vol:577, Issue:19, pages:411766, Elsevier

The structural, electronic and optical properties of Mn-doped ZnO thin films were studied using density functional theory (DFT) with Hubbard U method. Supercell model and substitutional method were employed to achieve the considered doping concentrations (x). Antiferromagnetic phase of Zn1−xMnxO (x = 0.125) structure was adopted at different geometry configurations. On the other hand, Zn1−xMnxO (x = 7, 10 and 12.5) thin films, with good uniformity, were fabricated using sol–gel spin coating technique. Both grain size and surface roughness were decreased with x, leading to the decrease of the average transmittance. Calculations revealed that Mn atoms tend to be close to each other around the O atom. Besides, Mn3d states were found to be rarely distributed around Fermi level. Furthermore, Mulliken analysis demonstrated the coexistence of both ionic and covalent bonding. Both materials presented a similar behavior for optical properties with a slight shift toward the lower energy by increasing x.

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Rabie AMARI , Bahri DEGHFEL , Abdelhafid MAHROUG , AMMAR Boukhari , Ahmad Azmin Mohamad, Noureddine Selmi, , (2020), Effects of Mn doping on the structural, morphological, electronic and optical properties of ZnO thin films by sol-gel spin coating method: An experimental and DFT+ U study, Physica B: Condensed Matter, Vol:577, Issue:15, pages:411766, North-Holland

ZnO and ZnCoO thin films 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 ions metal was maintained at 1.0 and a concentration of metal ions is 0.6 mol.L-1 . The XRD results showed that both films crystallized under hexagonal wurtzite structure and presented a preferential orientation along the c-axis with the maximum crystallite size was found is 25nm. Atomic force microscope (AFM) images revealed the good uniformity for both films, an increase of surface roughness is observed with doping. The average transmittance in the visible region was higher than 85% for both films and the optical band gap of Zinc oxide films decreased with Co doping. Photoluminescence of the films showed a ultraviolet (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. Ours thin films shows the best photocurrent properties.

Citation

Abdelhafid MAHROUG , Bahri DEGHFEL , ,(2019), Studies on structural, surface morphological, optical, luminescence and uv photodetection properties of sol gel oxides thin films,ICAMS 2018 – 7th International Conference on Advanced Materials and Systems,Romania

In this work, we have studied the influence of Mn doping on the structural, morphological, optical and photoluminescence (PL) properties of ZnO thin films. ZnO thin films with different concentrations of Manganese (0, 2 and 4 mol.%) were prepared by the sol–gel spin coating process and synthesized on glass substrates. By using an X-ray diffractometer (XRD) (Bruker 8 Advance) with Cu-kα radiation having a wavelength λ=1.5406 A°, the structural properties of the films were characterised. To evaluate the band gap, the optical transmission spectra were measured by an ultraviolet-visible (UV-vis) spectrophotometer (UV-3101 PC-Shimadzu) in the spectral range 300-800 nm. Photoluminescence (PL) measurements were recorded using a spectrofluorimeter (Perkin Elmer LS 50B) with the excitation wavelength of 325 nm.

Citation

Rabie AMARI , Abdelhafid MAHROUG , Bahri DEGHFEL , ,(2018), Effect of Mn Doping on the Structural and Optical Properties of ZnO thin Films,International Conference on Materials Science (ICMS2018),Ferhat Abbas Setif 1-Algeria

Magnesuim doped Zinc oxide thin films were prepared by sol-gel spin coating method

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Abdelhafid MAHROUG , Amari Rabie , Boukhari Ammar , Bahri DEGHFEL , elhadj.benrezgua@univ-msila.dz, ,(2018), Deposition and Characterization of Mg doped nanostructured thin films,International Conference on Materials Science 2018 (ICMS2018),Sétif, Algeria

Zn0.875Mn0.125O thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates using zinc acetate dehydrate [Zn(CH3COO)2·2H2O] and manganese acetate tetrahydrate [Mn(CH3COO)24H2O]as a starting material and doping source. Isopropanol and monoethanolamine (MEA) were used as solvent and stabilizer, respectively. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of Mn doping on the structural, electronic and optical properties of ZnO thin films. The obtained results are compared with those using first-principles calculation based on density functional theory (DFT) with local density approximation (LDA) plus Hubbard U (DFT–LDA+U) method. This latter represents the theoretical framework to deal with strongly correlated materials to predicted successfully the electronic properties of such materials.

Citation

Bahri DEGHFEL , ,(2018), Experimental and first principles study of structural, electronic and optical properties of Zn0.875Mn0.125O thin film,ICAMS 2018 – 7th International Conference on Advanced Materials and Systems,Romania

In this study, Manganese-doped Zinc oxide (ZnO) nanostructured thin films with different Mn doping concentrations (0, 1, 3, 5 and 7 mol.%) were synthesized on glass substrates by the sol–gel spin coating technique. The concentration of metal ions was fixed at 0.6 mol·L–1. Structural, surface morphological, optical and luminescence properties of the films were investigated by XRD, AFM, UV-Vis spectrometry and PL spectroscopy techniques. The XRD results showed that the films had hexagonal wurtzite structure and exhibited preferred orientation along the c-axis. Crystallite size, lattice parameters, strain and residual stress were influenced by Mn doping, where average crystallite size decreased from 45 to 10 nm with doping concentration. Atomic force microscope (AFM) images revealed the good uniformity for all the films, and reduction of grain size and surface roughness is observed with the increase of doping concentration. The average transmittance in the visible region was higher than 80% for all the films. Unlike the Urbach energy, the optical band gap of Zinc oxide films decreased with Manganese doping. The origin of ultraviolet, violet, blue and green emissions observed from photoluminescence spectra, and the effect of Mn doping on the luminescence properties and defects concentration were discussed in details. It is worth noting that the fabricated Zinc oxide (ZnO) thin films, which presented good properties, can be used for potential applications in optoelectronic devices.

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Abdelhafid MAHROUG , Amari Rabie , Boukhari Ammar , Bahri DEGHFEL , , (2018), Synthesis, Structural, Morphological, Electronic, Optical and Luminescence Properties of Pure and Manganese-Doped Zinc Oxide Nanostructured Thin Films: Effect of Doping, Journal of Nanoelectronics and Optoelectronics, Vol:13, Issue:5, pages:732, American Scientific Publishers

In this study, Manganese-doped Zinc oxide (ZnO) nanostructured thin films with different Mn doping concentrations (0, 1, 3, 5 and 7 mol.%) were synthesized on glass substrates by the sol–gel spin coating technique. The concentration of metal ions was fixed at 0.6 mol·L–1. Structural, surface morphological, optical and luminescence properties of the films were investigated by XRD, AFM, UV-Vis spectrometry and PL spectroscopy techniques. The XRD results showed that the films had hexagonal wurtzite structure and exhibited preferred orientation along the c-axis. Crystallite size, lattice parameters, strain and residual stress were influenced by Mn doping, where average crystallite size decreased from 45 to 10 nm with doping concentration. Atomic force microscope (AFM) images revealed the good uniformity for all the films, and reduction of grain size and surface roughness is observed with the increase of doping concentration. The average transmittance in the visible region was higher than 80% for all the films. Unlike the Urbach energy, the optical band gap of Zinc oxide films decreased with Manganese doping. The origin of ultraviolet, violet, blue and green emissions observed from photoluminescence spectra, and the effect of Mn doping on the luminescence properties and defects concentration were discussed in details. It is worth noting that the fabricated Zinc oxide (ZnO) thin films, which presented good properties, can be used for potential applications in optoelectronic devices.

Citation

Abdelhafid MAHROUG , Rabie AMARI , AMMAR Boukhari , Bahri DEGHFEL , L Guerbous, Nourddine Selmi, , (2018), Synthesis, Structural, Morphological, Electronic, Optical and Luminescence Properties of Pure and Manganese-Doped Zinc Oxide Nanostructured Thin Films: Effect of Doping, Journal of Nanoelectronics and Optoelectronics, Vol:13, Issue:5, pages:732-742, American Scientific Publishers

Transparent zinc oxide (ZnO) thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations (0.3–1.2 M) using zinc acetate dehydrate [Zn(CH3COO)2·2H2O] as precursor and isopropanol and monoethanolamine (MEA) as solvent and stabilizer, respectively. The molar ratio of zinc acetate dehydrate to MEA is 1.0. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of solution concentration on the structural and optical properties of the ZnO thin films. The obtained results of all thin films are discussed in detail and are compared with other experimental data.

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AMMAR Boukhari , Abdelhafid MAHROUG , AMMAR Boukhari , Bahri DEGHFEL , NOURREDINE SELMI, , (2018), Structural, optical and luminescence properties of ZnO thin films prepared by sol-gel spin-coating method: effect of precursor concentration, Chinese Physics Letters, Vol:35, Issue:, pages:016801, IOP Publishing

Zn0.875Mn0.125O thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates using zinc acetate dehydrate [Zn(CH3COO)2·2H2O] and manganese acetate tetrahydrate [Mn(CH3COO)24H2O]as a starting material and doping source. Isopropanol and monoethanolamine (MEA) were used as solvent and stabilizer, respectively. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of Mn doping on the structural, electronic and optical properties of ZnO thin films. The obtained results are compared with those using first-principles calculation based on density functional theory (DFT) with local density approximation (LDA) plus Hubbard U (DFT–LDA+U) method. This latter represents the theoretical framework to deal with strongly correlated materials to predicted successfully the electronic properties of such materials.

Citation

Bahri DEGHFEL , Abdelhafid MAHROUG , Rabie AMARI , AMMAR Boukhari , A. BENTABET, ,(2018), Experimental and first principles study of structural, electronic and optical properties of Zn0.875Mn0.125O thin film,ICAMS 2018 – 7th International Conference on Advanced Materials and Systems,Bucharest, ROMANIA

The structural, electronic, elastic and optical properties of pure and Mn-doped ZnO with a wurtzite structure were calculated by using first-principles calculation based on density functional theory (DFT) with local density approximation (LDA) [1] plus Hubbard U (DFT–LDA+U) method [2]. This latter represents the theoretical framework to deal with strongly correlated materials to predicted successfully the electronic properties of such materials. The wurtzite ZnO system is then doped with Mn at different sites. The obtained results were discussed and compared with earlier works.

Citation

Bahri DEGHFEL , AMMAR Boukhari , Rabie AMARI , Abdelhafid MAHROUG , A. Bentabet, ,(2017), First principles LDA+U study of structural, electronic, elastic and optical properties of Mn doped wurtzite ZnO.,Nanotechnology and nanomaterials» (NANO-2017),Ukraine - Chernivtsi