Browsing by Author "Benhaoua, Boubaker"

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A comparative study on structural and optical properties of ZnO and Al-doped ZnO thin films obtained by ultrasonic spray method using different solvents
(Urban & Fischer, 2014-07-01) Gahtar, Abdelouahab; Rahal, Achour; Benhaoua, Boubaker; Benramache, Said
Abstract Transparent conducting ZnO and Al doped ZnO thin films were deposited on glass substrate by ultrasonic spray method. The thin films with concentration of 0.1 M were deposited at 350 °C with 2 min of deposition time. The effects of ethanol and methanol solution before and after doping on the structural, optical and electrical properties were examined. The DRX analyses indicated that ZnO films have nanocrystalline nature and hexagonal wurtzite structure with (1 0 0) and (0 0 2) preferential orientation corresponding to ZnO films resulting from methanol and ethanol solution, respectively. The crystallinity of the thin films improved with methanol solution after doping to (0 0 2) oriented. All films exhibit an average optical transparency about 90%, in the visible range. The band gaps values of ZnO thin films are increased after doping from 3.10 to 3.26 eV and 3.27 to 3.30 eV upon Al doping obtained by ethanol and methanol solution, respectively. The electrical conductivity increase from 7.5 to 15.2 (Ω cm)−1 of undoped to Al doped ZnO thin films prepared by using ethanol solution. However, for the methanol solution; the electrical conductivity of the film is stabilized after doping.
Effect of fluorine doping on the structural, optical and electrical properties of SnO2 thin films prepared by spray ultrasonic
(Superlattices and Microstructures, 2014-06) Benhaoua, Atmane; Rahal, Achour; Benhaoua, Boubaker; Jlassi, Mohamed
Abstract The undoped and fluorine doped tin oxide (SnO2) thin films are synthesized by using cost-effective spray ultrasonic technique; the films are sprayed on heated glass substrates at 480 °C. The dependence of structural, optical and electrical properties of SnO2 films on the concentration of fluorine is investigated. X-ray diffraction, Optical absorption, four-point probe and Hall Effect studies have been performed on undoped and fluorine doped SnO2 (FTO) films. X-ray diffraction pattern reveals the presence of cassiterite structure with (2 0 0) as preferential orientation for FTO films. The crystallite size varies from 10.3 to 27.12 nm and was affected by F concentration which was lying between 0 and 12 wt.%. All films exhibit optical transmission T(λ) more than 83.9% in visible region; the optically estimated film thickness varies from 700 to 975 nm for the same given time (3 min deposition) and band gap (Eg) varies from 3.651 to 3.902 eV. The electrical study reveals that the films have n-type electrical conductivity and depend upon fluorine concentration too. The sprayed FTO film doped at 6 wt.% has the minimum resistivity of 1.47 × 10−3 Ω cm and minimum resistance sheet (Rsh) of 21 Ω/cm2 whereas the carrier concentration and mobility were about 2.04 × 1019 cm−3 and 208.4 cm2 V−1 s−1 respectively.
Effect of iron doping on tin oxide thin films
(University of Eloued جامعة الوادي, 2018-12-10) Segueni, Leila; Benhaoua, Boubaker; Allag, Nassiba; Rahal, Achour; Benhaoua, Atmane
In this study, Undoped tin oxide (SnO2) and iron (Fe) doped tin oxide thin films were deposited on heated glass using spray pyrolysis technique. SnCl2 and FeCl3 were used as sources of SnO2 and Fe doping respectively. Effects of dopant on the optical, structural and opto-electrical properties of 0,0.2 and 0.4 wt.% Fe-doped SnO2 thin films were investigated. Optical transmittance spectra of the thin films showed high transparency of about 80-90% in visible region. The optical gap of 0,0.2and 0.4 wt. % Fe-doped SnO2 thin films were found to be in 3.78-3.67 eV range. X-ray diffraction patterns showed that both undoped SnO2 and Fe-doped SnO2 thin films, were polycrystalline with cassiterite tetragonal crystal structure. The preferential orientation for undoped SnO2 was along (211) plane whereas Fe-doped SnO2 preferential orientations were along (110) planes. The calculated grain sizes were in 35.63- 30.03 nm average. Fe-doped SnO2 thin films are promising to be used as smart windows , gas sensor and water treatment
Effect of substrate temperature on the stability of transparent conducting cobalt doped ZnO thin films
(IOP Publishing, 2012-09-01) Benramache, Said; Benhaoua, Boubaker; Chabane, Foued
Transparent conducting Co doped ZnO thin films have been fabricated by Ultrasonic spray. The thin films were deposited at three different substrate temperatures of 300, 350 and 400 ℃. The obtained films had a hexagonal wurtzite structure with a strong (002) preferred orientation. The maximum crystallite size value of the film deposited at 350 ℃ is 55.46 nm. Spectrophotometer (UV-vis) of a Co doped ZnO film deposited at 350 ℃ shows an average transmittance of about 90%. The band gap energy increased from 3.351 to 3.362 eV when the substrate temperature increased from 300 to 350 ℃. The electrical conductivity of the films deposited at 300, 350 and 400 ℃ were 7.424, 7.547 and 6.743 (Ω·cm)-1 respectively. The maximum activation energy value of the films at 350 ℃ was 1.28 eV, indicating that the films exhibit a n-type semiconducting nature.
The effects of solvent nature on spray-deposited ZnO thin film prepared from Zn (CH3COO)2, 2H2O
(Urban & Fischer, 2014-01-01) Benramache, Said; Rahal, Achour; Benhaoua, Boubaker
Transparent conducting zinc oxide was deposited on glass substrate by ultrasonic spray method. The ZnO samples with concentration of 0.1 M were deposited at 300, 350 and 400 °C with 2 min of deposition time. The effects of substrate temperature, ethanol and methanol solution on the structural, electrical and optical properties were examined. The DRX analyses indicated that ZnO films have polycrystalline nature and hexagonal wurtzite structure with (1 0 0) and (0 0 2) preferential orientation corresponding to ZnO films resulting from methanol and ethanol, respectively. The crystallinity of the thin films improved with ethanol solution. All films exhibit an average optical transparency about 80%, in the visible range. The band gap energy of ZnO films obtained with methanol solution higher than of ethanol solution for all the films. The electrical resistivity decrease with ZnO obtained from ethanol indicated; due to the maximum crystallite size retched at this point.
Feasibility and Modeling studies for thermal performance of an earth to air heat exchanger in South East Algeria
(University of Eloued جامعة الوادي, 2018-12-10) hadjadj, Abdessamia; Benhaoua, Boubaker; Attia, Abdelmalek
This paper presents a study on the energy performance of an earth-air heat exchanger (EAHE), In order to check the temperature factor in their effect on heat exchangers, the aim of this paper is to influence the ambient temperature on the performance of EAHE systems in arid and semi-arid climatic zones. So, our use CFD modeling techniques were used to assess the impacts of the parameters of dimensioning on the performance of earth-to-air heat exchanger (EAHE). Assume that exchangers are made (polyvinyl chloride–PVC) As its length a 50 m conduct length, 80 mm diameter and 3 m burial depth). The simulation results were validated by comparison with experimental results, Results show that the specific heat exchange is used to cool in an arid zone (south-east of Algeria). When the ambient temperature varies between 36°C and 40 °C, the cooling temperature varies between 25°C and 28 °C. Temperature difference inlet and outlet air exchanger 12°C, these values are quite acceptable with minimal consumption of electrical energy
Influence of annealing temperature on structural and optical properties of ZnO: In thin films prepared by ultrasonic spray technique
(Superlattices and Microstructures, 2012-12) Benramache, Said; Benhaoua, Boubaker
Transparent conducting indium doped zinc oxide was deposited on glass substrate by ultrasonic spray method. The In doped ZnO samples with indium concentration of 3 wt.% were deposited at 300, 350 and 400 °C with 2 min of deposition time. The effects of substrate temperature and annealing temperature on the structural, electrical and optical properties were examined. The DRX analyses indicated that In doped ZnO films have polycrystalline nature and hexagonal wurtzite structure with (0 0 2) preferential orientation and the maximum average crystallite size of ZnO: In before and annealed at 500 °C were 45.78 and 55.47 nm at a substrate temperature of 350 °C. The crystallinity of the thin films increased by increasing the substrate temperature up 350 °C, the crystallinity improved after annealing temperature at 500 °C. The film annealed at 500 °C and deposited at 350 °C show lower absorption within the visible wavelength region. The band gap energy increased from Eg = 3.25 to 3.36 eV for without annealing and annealed films at 500 °C, respectively, indicating that the increase in the transition tail width. This is due to the increase in the electrical conductivity of the films after annealing temperature.
Influence of growth time on crystalline structure, conductivity and optical properties of ZnO thin films
(IOP Publishing, 2013-02-01) Benramache, Said; Chabane, Foued; Benhaoua, Boubaker; Lemmadi, Fatima Z
This paper examines the growth of ZnO thin films on glass substrate at 350 °C using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are (002) oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 Ω·cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 °C has been reported.
An optimized perovskite solar cell designs for high conversion efficiency
(Superlattices and Microstructures, 2019-05) Hima, Abdelkader; Lakhdar, Nacereddine; Benhaoua, Boubaker; Saadoune, Achour; Kemerchou, Imad; Rogti, Fatiha
This paper reports the simulation and optimization of an organic/inorganic perovskite-based photovoltaic solar cell. Several structures for PSC are found in literature in order to enhance the conversion efficiency. The objectif of this work is to study and investigate different structures of solar cells based on perovskite materials to improve their performances. The simulated solar cell is made by sandwiching TiO2/Perovskite/spiro-OMeTAD layers where TiO2 is the electron transport layer (ETL), spiro-OMeTAD is the hole transport layer (HTL) and both CH3NH3PbI3 CH3NH3SnI3 are the perovskite (PVK) absorber layers. Therefore, the layer thicknesses of different materials are modified in order to find the better conversion efficiency of solar cells. The obtained results show that layer thicknesses that provide the maximum power conversion efficiency of 18.16% and 9.56% for both perovskite materials CH3NH3PbI3 and CH3NH3SnI3, respectively are 200 nm, 100 nm and 500 nm for spiro-OMeTAD, TiO2 and PVK materials, respectively. The numerical simulation was performed using the ATLAS device simulation software.
Preparation of transparent conducting ZnO:Al films on glass substrates by ultrasonic spray technique
(IOP Publishing, 2013-07-01) Gahtar, Abdelouahab; Benramache, Said; Benhaoua, Boubaker; Chabane, Foued
Transparent conductive Al doped ZnO thin films were deposited by ultrasonic spray technique. Conditions of preparation have been optimized to get good quality. A set of aluminum (Al) doped ZnO (between 0 and 5 wt%) thin films were grown on glass substrate at 350 °C. Nanocrystalline films with a hexagonal wurtzite structure show a strong (002) preferred orientation. The maximum value of grain size G = 32.05 nm is attained of Al doped ZnO film with 3 wt%. All the films have low absorbance in the visible region, thus the films are transparent in the visible region; the band gap energy increased from 3.10 to 3.26 eV when Al concentration increased from 0 to 3 wt%. The electrical conductivity of the films increased from 7.5 to 15.2 (Ω·cm)−1. So the best results are achieved in Al doped ZnO film with 3 wt%.
Preparation of transparent, conductive ZnO:Co and ZnO:In thin films by ultrasonic spray method
(Journal of Nanostructure in Chemistry. Springer Berlin Heidelberg, 2013-12) Benramache, Said; Benhaoua, Boubaker; Bentrah, Hamza
This paper examines the growth of undoped and doped thin films with (Co and In) on glass substrate at 350°C using ultrasonic spray technique. We have investigated the influence of doping concentrations ranging from 0 to 4 wt.% on structural, optical, and electrical properties of ZnO thin films. Zinc acetate dehydrate, CoCl3 4H2O or InCl3, ethanol, and monoethanolamine were used as a starting materials, dopant source, solvent, and stabilizer, respectively. The X-ray diffraction analysis indicated that the undoped and doped ZnO thin films have polycrystalline nature and hexagonal wurtzite structure with (002) preferential orientation. The maximum average crystallite sizes of ZnO:Co and ZnO:In were 55.46 and 45.78 nm at concentrations of 2 wt.% Co and 3 wt.% In, respectively, indicating that the crystallinity of doped films improved after doping. The optical absorption spectra showed that all undoped and doped ZnO films are transparent within the visible wavelength region. The band gap energy of ZnO:Co thin films increased after doping from 3.25 to 3.36 eV; however, the optical gap of ZnO:In decreases after doping from 3.25 to 3.18 eV, indicating the increase and decrease, respectively, in the transition tail width. The electrical conductivity of doped films is stabilized after doping. Transparent, conductive Co-doped ZnO thin films deposited by ultrasonic spray technique are of good quality.
Sand dunes effect on the productivity of a single slope solar distiller
(Springer Berlin Heidelberg, 2020-04) Khechekhouche, Abderrahmane; Benhaoua, Boubaker; Manokar, Muthu; Sathyamurthy, Ravishankar; Kabeel, Abd Elnaby; Driss, Zied
Access to drinking water in many parts of the globe is shrinking over the years and much of the water resources are polluted or unpurified. North Africa is facing a huge water shortage due to drought and climate change. Water desalination has become very popular and serves as solar distillation which is proving to be an economical, simple and ecological technique, especially in rural and remote areas. Significant efforts have been made by many researchers in various laboratories to increase and improve the productivity of solar greenhouse distillation. In the present work, emphasis has been placed on the study of a single slope solar distiller having as dimension 50 × 50 cm, in the thickness of the impure water is 1 cm. Natural sand dunes from the El Oued South region of Algeria have been tested as a factor of efficiency improvement. A layer of this sand was deposited on the bottom of the distiller covering the whole surface on which the submit water is emerged. The results show that the productivity of distilled water has unfortunately decreased by 1.46 times.
The structural, optical and electrical properties of nanocrystalline ZnO: Al thin films
(Academic Press, 2014-04) Benhaoua, Boubaker; Rahal, Achour; Benramache, Said
The Al doped ZnO thin films were deposited by ultrasonic spray technique. The influence of Al doping on structural, optical and electrical properties of the ZnO thin films was studied. A set of Al doped ZnO (0–3.5 wt.%) were deposited at 350 °C. Nanocrystalline films with a hexagonal wurtzite structure with a strong (0 0 2) preferred orientation were observed after Al doping. The maximum value of grain size (33.28 nm) is attained with Al doped ZnO at 3 wt.%. Texture coefficient TC(h k l) of the four major peaks where evaluated. Optically, in visible region the transmissions spectra T(λ) show that the whole doped films exhibit lower values than the non doped one which has as transmittance more than 80%; whereas in the same region the optical transmissions of the doped films are affected by the doping ration. The band gap (Eg) increased after doping from 3.267 to 3.325 eV with increasing concentration of doping from 0 to 2.75 wt.%, respectively, according to the Burstein–Moss effect (blue shift of Eg) then beyond 3 wt.% in doping the band gap exhibit a slight decreasing due to the coexistence of Roth and Burstein–Moss effect. The electrical resistivity of the films decreased from 20 to 5.26 (Ω cm). The best results are achieved with 2.75 wt.% Al doped ZnO film.