The effect of iron concentration on the microstructural and structural properties of ZnO for electrolysis and photodetector applications was investigated.The thin layers of un-doped and doped ZnO with different percen...The effect of iron concentration on the microstructural and structural properties of ZnO for electrolysis and photodetector applications was investigated.The thin layers of un-doped and doped ZnO with different percentages of Fe(2,4,and 6 wt.%)were deposited by spin-coating on glass substrates.Sample characterization was done by X-ray diffraction(XRD),atomic force microscopy(AFM),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),UV−Vis absorption spectra and X-ray photoelectron spectroscopy(XPS).Structural measurements by XRD showed that all the layers were composed of polycrystallines with a hexagonal Wurtzite structure.Two new peaks were also discovered after the doping process belonging to the Fe_(2)O_(4)(400)and(440)crystal phase.Morphological analysis showed that the surface roughness values of ZnO layers ranged between 8 and 45 nm.XPS studies confirmed the presence of Fe in 3+states in ZnO layers.An average transmittance of 90%was measured by UV−Vis in the wavelength range of 200−900 nm.The values of the energy gap(Eg)decreased with an increase in the concentration of Fe.AFM topography results confirmed that ZnO-based thin layers had a relatively uniform surface.The efficiency of these samples has been confirmed for their use in many electrical applications,including photodetectors and electrolysis of contaminated solutions.展开更多
Composites consisting of carbopol (CP) and ceramic titanium dioxide nanoparticles, TiO2 have been investigated. The CP-TiO2, organic-inorganic hybrid composites have been prepared in DMF by heating the mixture with a ...Composites consisting of carbopol (CP) and ceramic titanium dioxide nanoparticles, TiO2 have been investigated. The CP-TiO2, organic-inorganic hybrid composites have been prepared in DMF by heating the mixture with a constant rate of 1。C/min, up to 30。C, 45。C, 60。C, 80。C, 100。C and 120。C. Proprieties such as absorption, structure and external aspect of the obtained materials were investigated by Uv-vis, FTIR, DRX and SEM analyses. The X-ray diffraction patterns confirmed that the TiO2 nanoparticles maintained their original tetragonal anatase-type crystalline structure in the composites. The chemical structure of the obtained materials was determined by ATR-FTIR spectroscopy. The influence of TiO2 nanoparticles on the thermal proprieties of carbopol matrix was investigated using thermo-gravimetric analysis and differential scanning calorimetry. The glass transition temperature (Tg) of the carbopol matrix was considerably increased by the presence of ceramic feller nanoparticles and its thermal stability was significantly improved. Furthermore the water loss which represents 7.56% of the weight loss in pure CP at 100。C was avoided in the CP-TiO2 nanocomposites at this same temperature. This important finding revealed that ceramic fellers blocked the water loss in the modified carbopol nanocomposites, which stayed stable till 200。C.展开更多
Local Binary Patterns (LBPs) have been highly used in texture classification <span style="font-family:Verdana;">for their robustness, their ease of implementation an</span><span style="fo...Local Binary Patterns (LBPs) have been highly used in texture classification <span style="font-family:Verdana;">for their robustness, their ease of implementation an</span><span style="font-family:Verdana;">d their low computational</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">cost. Initially designed to deal with gray level images, several methods based on them in the literature have been proposed for images having more than one spectral band. To achieve it, whether assumption using color information or combining spectral band two by two was done. Those methods use micro </span><span style="font-family:Verdana;">structures as texture features. In this paper, our goal was to design texture features which are relevant to color and multicomponent texture analysi</span><span style="font-family:Verdana;">s withou</span><span style="font-family:Verdana;">t any assumption.</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Based on methods designed for gray scale images, we find the combination of micro and macro structures efficient for multispectral texture analysis. The experimentations were carried out on color images from Outex databases and multicomponent images from red blood cells captured using a multispectral microscope equipped with 13 LEDs ranging </span><span style="font-family:Verdana;">from 375 nm to 940 nm. In all achieved experimentations, our propos</span><span style="font-family:Verdana;">al presents the best classification scores compared to common multicomponent LBP methods.</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">99.81%, 100.00%,</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">99.07% and 97.67% are</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">maximum scores obtained with our strategy respectively applied to images subject to rotation, blur, illumination variation and the multicomponent ones.</span>展开更多
The photoelectric properties of multilayer organic photovoltaic cells (OPV cells) were studied. The active organic layers consisted of a planar heterojunction between a layer of Meso-Tetrakis(4-BromoPhenyl) Zinc(II) P...The photoelectric properties of multilayer organic photovoltaic cells (OPV cells) were studied. The active organic layers consisted of a planar heterojunction between a layer of Meso-Tetrakis(4-BromoPhenyl) Zinc(II) Porphyrin (BrPhPZn) as electron donor (ED) and a layer fullerene molecules. The devices were fabricated in a high vacuum by thermal sublimation, a technique that allows multilayer devices realization easily by successive depositions, and it does not require solvents, achieving purer films with reproducible characteristics. Taking into account that the anodic contact, a key factor for cell efficiency, is favored by the inclusion of a thin anodic buffer layer (ABL), the effect on the yield after including one or two (ABL): MoO3 or MoO3-CuI layers was studied. The cell which has the best photovoltaic characteristics has a BrPhPZn (ED) thickness of only 12.5 nm. This small thickness is related with the low conductivity of this organic molecule. On the other hand, including a thin MoO3-CuI bilayer increased, such device’s efficiency in a 200%, with regard to a cell without ABL, getting for one cell ITO/MoO3-CuI/BrPhPZn/C60/Alq3/Al, with a 1.03% yield.展开更多
基金the support received from the Researchers Supporting Project(No.RSP2024R404),King Saud University,Riyadh,Saudi Arabia。
文摘The effect of iron concentration on the microstructural and structural properties of ZnO for electrolysis and photodetector applications was investigated.The thin layers of un-doped and doped ZnO with different percentages of Fe(2,4,and 6 wt.%)were deposited by spin-coating on glass substrates.Sample characterization was done by X-ray diffraction(XRD),atomic force microscopy(AFM),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),UV−Vis absorption spectra and X-ray photoelectron spectroscopy(XPS).Structural measurements by XRD showed that all the layers were composed of polycrystallines with a hexagonal Wurtzite structure.Two new peaks were also discovered after the doping process belonging to the Fe_(2)O_(4)(400)and(440)crystal phase.Morphological analysis showed that the surface roughness values of ZnO layers ranged between 8 and 45 nm.XPS studies confirmed the presence of Fe in 3+states in ZnO layers.An average transmittance of 90%was measured by UV−Vis in the wavelength range of 200−900 nm.The values of the energy gap(Eg)decreased with an increase in the concentration of Fe.AFM topography results confirmed that ZnO-based thin layers had a relatively uniform surface.The efficiency of these samples has been confirmed for their use in many electrical applications,including photodetectors and electrolysis of contaminated solutions.
文摘Composites consisting of carbopol (CP) and ceramic titanium dioxide nanoparticles, TiO2 have been investigated. The CP-TiO2, organic-inorganic hybrid composites have been prepared in DMF by heating the mixture with a constant rate of 1。C/min, up to 30。C, 45。C, 60。C, 80。C, 100。C and 120。C. Proprieties such as absorption, structure and external aspect of the obtained materials were investigated by Uv-vis, FTIR, DRX and SEM analyses. The X-ray diffraction patterns confirmed that the TiO2 nanoparticles maintained their original tetragonal anatase-type crystalline structure in the composites. The chemical structure of the obtained materials was determined by ATR-FTIR spectroscopy. The influence of TiO2 nanoparticles on the thermal proprieties of carbopol matrix was investigated using thermo-gravimetric analysis and differential scanning calorimetry. The glass transition temperature (Tg) of the carbopol matrix was considerably increased by the presence of ceramic feller nanoparticles and its thermal stability was significantly improved. Furthermore the water loss which represents 7.56% of the weight loss in pure CP at 100。C was avoided in the CP-TiO2 nanocomposites at this same temperature. This important finding revealed that ceramic fellers blocked the water loss in the modified carbopol nanocomposites, which stayed stable till 200。C.
文摘Local Binary Patterns (LBPs) have been highly used in texture classification <span style="font-family:Verdana;">for their robustness, their ease of implementation an</span><span style="font-family:Verdana;">d their low computational</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">cost. Initially designed to deal with gray level images, several methods based on them in the literature have been proposed for images having more than one spectral band. To achieve it, whether assumption using color information or combining spectral band two by two was done. Those methods use micro </span><span style="font-family:Verdana;">structures as texture features. In this paper, our goal was to design texture features which are relevant to color and multicomponent texture analysi</span><span style="font-family:Verdana;">s withou</span><span style="font-family:Verdana;">t any assumption.</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Based on methods designed for gray scale images, we find the combination of micro and macro structures efficient for multispectral texture analysis. The experimentations were carried out on color images from Outex databases and multicomponent images from red blood cells captured using a multispectral microscope equipped with 13 LEDs ranging </span><span style="font-family:Verdana;">from 375 nm to 940 nm. In all achieved experimentations, our propos</span><span style="font-family:Verdana;">al presents the best classification scores compared to common multicomponent LBP methods.</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">99.81%, 100.00%,</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">99.07% and 97.67% are</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">maximum scores obtained with our strategy respectively applied to images subject to rotation, blur, illumination variation and the multicomponent ones.</span>
文摘The photoelectric properties of multilayer organic photovoltaic cells (OPV cells) were studied. The active organic layers consisted of a planar heterojunction between a layer of Meso-Tetrakis(4-BromoPhenyl) Zinc(II) Porphyrin (BrPhPZn) as electron donor (ED) and a layer fullerene molecules. The devices were fabricated in a high vacuum by thermal sublimation, a technique that allows multilayer devices realization easily by successive depositions, and it does not require solvents, achieving purer films with reproducible characteristics. Taking into account that the anodic contact, a key factor for cell efficiency, is favored by the inclusion of a thin anodic buffer layer (ABL), the effect on the yield after including one or two (ABL): MoO3 or MoO3-CuI layers was studied. The cell which has the best photovoltaic characteristics has a BrPhPZn (ED) thickness of only 12.5 nm. This small thickness is related with the low conductivity of this organic molecule. On the other hand, including a thin MoO3-CuI bilayer increased, such device’s efficiency in a 200%, with regard to a cell without ABL, getting for one cell ITO/MoO3-CuI/BrPhPZn/C60/Alq3/Al, with a 1.03% yield.
