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Mejda Ajili Najoua Turki Kamoun 《Journal of Materials Science: Materials in Electronics》2014,25(9):3840-3845
Indium sulfide (In2S3) is a good window or buffer layer for photovoltaic application. In this work, β-In2?xAlxS3 thin films with different thicknesses (400, 442, 646 and 714 nm) are successfully synthesized on heated glass substrates using a chemical spray pyrolysis technique. The thin film thickness effect on the structural, optical and photoluminescence (PL) properties of β-In2?xAlxS3 material is studied. The X-ray diffraction patterns suggest the formation of β-In2S3 cubic phase preferentially oriented towards (400) direction. The level of the residual dislocation seems to be reduced to 3.12 × 109 lines mm?2 for the optimum thickness (646 nm) for which the β-In2?xAlxS3 film crystallinity is the best one. In order to enhance the electrical properties, β-In2?xAlxS3 layers are annealed in air at 400 °C for different annealing times (15, 30 and 45 min). The minimum resistivity, maximum Hall mobility and carrier concentration are found for β-In2?xAlxS3 films annealed for 30 min. All samples have high transmittance of about 75 % but the wide band gap (Eg = 3.32 eV) is obtained for this optimum thickness. This result indicates good optical quality of β-In2?xAlxS3 layers. Defects-related PL properties are also discussed. 相似文献
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Anis Akkari Cathy Guasch Michel Castagne Najoua Kamoun-Turki 《Journal of Materials Science》2011,46(19):6285-6292
Multilayers of zinc blend SnS crystalline thin film have been deposited onto glass substrates by a chemical bath deposition (CBD) method. The envelope method, based on the optical transmission spectrum taken at normal incidence, has been successfully applied to determine the layer thickness and to characterize optical properties of thin films having low surface roughness. Optical constants such as refractive index n, extinction coefficient k, as well as the real (??r) and imaginary (??i) parts of the dielectric constant were determined from transmittance spectrum using this method. Obtained low value of the extinction coefficient in the transparency domain is a good indication of film surface smoothness and homogeneity. To perform the heterojunction structure based on SnS absorber material, cubic In2S3:Al was deposited on SnO2:F/glass as window layer using CBD with different aluminum content. Optical properties of these films were evaluated. 相似文献
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Najoua Sbei Monia Chebbi Youssef Ben Smida Youssef Arfaoui Khaled Boujlel 《Journal of Sulfur Chemistry》2017,38(2):152-162
We report a simple method for the synthesis of alkyl-2-(2-imino-4-oxothiazolidin-5-ylidene) acetate derivatives 3 in good yields under mild conditions. The electrogenerated cyanomethyl base (EGB), obtained from electroreduction of acetonitrile-0.1?M TBABF4, assists the reaction between thiourea derivatives 1 and dialkyl acetylene dicarboxylate 2. The expected products, 3/4, and the structure obtained from X-ray diffraction confirm that the main products are the five-membered heterocycles 3. Furthermore, a mechanism, to explain the reaction pathways, is proposed based on the thermodynamic and kinetic data obtained from quantum calculations. 相似文献
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Anis Akkari Meriem Reghima Cathy Guasch Najoua Kamoun-Turki 《Journal of Materials Science》2012,47(3):1365-1371
SnS: Cu thin films have been successfully prepared on Pyrex substrates using low cost chemical bath deposition (CBD) technique
with different copper doped concentration (y = [Cu]/[Sn] = 5%, 6%, 8%, 9% and 10%). The structure, the surface morphology and the optical properties of the SnS:Cu films
were studied by X-ray diffraction (XRD), atomic force microscopy (AFM) and spectrophotometer measurements, respectively. To
obtain a thickness of the order of 780 ± 31 nm for absorber material in solar cell devices, a system of multilayer has been
prepared. It is found that the physical properties of tin sulphide are affected by Cu-doped concentration. In fact, X-ray
diffraction study showed that better cristallinity in zinc blend structure with preferential orientations (111)ZB and (200)ZB, was obtained for y equal to 6%. According to the AFM analysis we can remark that low average surface roughness (RMS)value of SnS(ZB) thin film
obtained with Cu-doped concentrations equal to y = 6%, is about of 54 nm. Energy dispersive spectroscopy (EDS) showed the existence of Cu in the films. Optical analyses by
means of transmission T(λ) and reflection R(λ) measurements show 1.51 eV as a band gap value of SnS:Cu(6%) which is nearly
equal to the theoretical optimum value of 1.50 eV for efficient light absorption. On the other hand, Cu-doped tin sulphide
exhibits a high absorption coefficient up to 2 × 106 cm−1, indicating that SnS:Cu can be used as an absorber thin layer in photovoltaic structure such as SnS:Cu/ZnS/SnO2:F and SnS:Cu/In2S3/SnO2:F, where ZnS and In2S3 are chemically deposited in a previous studies. 相似文献
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Baligh Touati Abdelaziz Gassoumi Najoua Kamoun Turki 《Journal of Materials Science: Materials in Electronics》2017,28(24):18387-18395
The present work reports on the chemical synthesizes of (0–8 at.%) silver (Ag)-doped PbS thin films with tunable opto-electrical properties. From the X-ray diffraction analyses, it was understood that the preferred growth orientation of Ag:PbS films was dependent on the Ag doping concentration. The variation in the Ag:PbS films orientation was reflected in the film morphology as observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM studies revealed that the variation in Ag concentration lead to different grain shapes for different grain orientations. The AFM study showed that the RMS roughness of the undoped PbS film has been reduced considerably due to silver doping. From the optical studies, a widening in the optical band gap was revealed after Ag-doping due to the quantum confinement effect. It was obtained that 4 at.% Ag-doped PbS thin films display an optimum band gap value of 1.45 eV. As for electrical characterization result, the resistivity reduces and the carrier density improved with 4 at.% Ag concentration. Based on all the data, it was concluded that the 4 at.% Ag-doped PbS thin film showed the best morphological, optical and electrical behavior, which recommend it as an active layer for solar cell devices. 相似文献
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