In this work, (Cu1-xAgx)2ZnSnSe4 (CAZTSe) alloys with various silver content (x= 0.0, 0.1and 0.2) have been prepared by reacting their high purity elements (Cu, Ag, Zn, Sn and Se) in an evacuated quartz tube under pressure of 10 -3Torr. The composition of the prepared alloys was determined by energy dispersive X-ray spectroscopy (EDXS) analysis, the results were close to the theoretical values. CAZTSe thin films with a thickness of 800 nm were deposited by thermal evaporation technique on glass substrates at room temperature (RT) with a deposition rate of 0.53nm/sec. Similarly, CdS thin films were deposited with a thickness of 100 nm on the same substrates at RT with a deposition rate of 0.3nm/sec from ready-made CdS alloy powder. All prepared thin films were annealed at temperatures of 373K and 473K under vacuum (10-3Torr) for 1h. X-ray analysis showed that all CAZTSe alloys and their thin films were polycrystalline and have the tetragonal structure with preferential orientation in the (112) direction, while all thin CdS films were polycrystalline and have the hexagonal structure with preferential orientation in the (002) direction. The scanning electron microscopy (SEM) technique was used to study the surface morphology of all prepared CAZTSe films, while the atomic force microscopy (AFM) technique was used to study the surface topography of all prepared CAZTSe and CdS films. SEM results revealed that CAZTSe films had uniform surface features with irregular sized grains, while AFM results showed that the surface roughness and the average grain size of CAZTSe and CdS thin films increased with increasing Ag content for CAZTSe thin films and annealing temperature for CAZTSe and CdS thin films. The absorbance and transmittance spectra for CAZTSe and CdS thin films were recorded in the wavelength ranges of (400-1100) nm and (350- 1100) nm, respectively. Optical measurements showed that all CAZTSe and CdS thin films have a direct energy gap (Eg) that decreased with increasing silver content for CAZTSe thin films and annealing temperature (Ta) for both types of prepared thin films, so it decreased from 1.73 eV to1.5 eV when x content increased from 0.0 to 0.2 and decreased from 1.5 eV to1.46 eV and from 2.47 eV to 2.38 eV when Ta increased from RT to 473K for CAZTSe thin films with x content equal to 0.2 and CdS thin films, respectively. Optical constants such as extinction coefficient, refractive index and dielectric constant were calculated for all prepared thin films. The measurements of the electrical properties for prepared films showed that the D.C electrical conductivity (σd.c) increased with increasing Ag content for CAZTSe thin films and annealing temperature for both types of thin films. So the electrical conductivity changed from 1.1276*10-2 (Ω.cm)-1 to 28.9266*10-2 (Ω.cm)-1 when x changed from 0.0 to 0.2 and changed from 28.9266*10-2 (Ω.cm)-1 to 57.4599*10-2 (Ω.cm)-1 and from 4.0476*10-4 (Ω.cm)-1 to 9.4227*10-4 (Ω.cm)-1 when Ta changed from RT to 473K for CAZTSe thin films with Ag content equal to 0.2 and CdS thin films, respectively. The prepared thin films have two activation energies (Ea1 & Ea2) in the temperature ranges of (318-488)K and (313-443)K for CAZTSe and CdS films, respectively. The results of Hall effect for CAZTSe thin films showed that all films were of acceptor type and the concentration of holes in them decreased with increasing silver content and annealing temperature, while CdS thin films were of donor type and the concentration of electrons in them increased with increasing annealing temperature. In this research, solar cells were fabricated from CdS/CAZTSe/Si structurThe C-V measurements revealed that all prepared heterojunctions were of the abrupt type and the junction capacitance and carrier concentration reduced while the width of depletion region and the built-in potential increased with increasing the silver content and annealing temperature. The current-voltage characteristics under dark condition of CAZTSe heterojunctions showed that both the ideality factor and saturation current decreased with increasing Ag content and annealing temperature. While,The current-voltage characteristics under dark condition of CAZTSe heterojunctions showed that both the ideality factor and saturation current decreased with increasing Ag content and annealing temperature. While, the current-voltage measurements under illumination showed that the performance of heterojunction solar cell improved with increasing Ag content and annealing temperature. The result indicated that the prepared solar cell with 0.2 Ag content and 473K annealing temperature exhibited the highest efficiency (η = 2.827%) compared to other prepared solar cells
This study showed the spreading of head lice in pupils of primary schools of Al-Nassirya city. The results showed that the percentage of males infected with lice was (5.4 %) and (9 %) for females. Also was obtained difference at age groups which we found maximum percentage of infection at age between (8 – 11) year. The highest infection for the hair tall at medium tall for both sex which the ratio (35.2 %) while for both sex with ratio (25 %) for girls. While the highest percentage for straight hair was (14.8 %) for girls
The catalytic cracking of three feeds of extract lubricating oil, that produced as a by-product from the process of furfural extraction of lubricating oil base stock in AL-Dura refinery at different operating condition, were carried out at a fixed bed laboratory reactor. The initial boiling point for these feeds was 140 ºC for sample (1), 86 ºC for sample (2) and 80 ºC for sample (3). The catalytic cracking processes were carried out at temperature range 325-400 ºC and initially at atmospheric pressure after 30 minutes over 9.88 % HY-zeolite catalyst load. The comparison between the conversion at different operating conditions of catalytic cracking processes indicates that a high yield was obtained at 375°C, according to gasoline pr
... Show MoreThe aim of this paper is to present a new methodology to find the private key of RSA. A new initial value which is generated from a new equation is selected to speed up the process. In fact, after this value is found, brute force attack is chosen to discover the private key. In addition, for a proposed equation, the multiplier of Euler totient function to find both of the public key and the private key is assigned as 1. Then, it implies that an equation that estimates a new initial value is suitable for the small multiplier. The experimental results show that if all prime factors of the modulus are assigned larger than 3 and the multiplier is 1, the distance between an initial value and the private key
... Show MoreNanofluids are proven to be efficient agents for wettability alteration in subsurface applications including enhanced oil recovery (EOR). Nanofluids can also be used for CO2-storage applications where the CO2-wet rocks can be rendered strongly water-wet, however no attention has been given to this aspect in the past. Thus in this work we presents contact angle (θ) measurements for CO2/brine/calcite system as function of pressure (0.1 MPa, 5 MPa, 10 MPa, 15 MPa, and 20 MPa), temperature (23 °C, 50 °C and 70 °C), and salinity (0, 5, 10, 15, and 20% NaCl) before and after nano-treatment to address the wettability alteration efficiency. Moreover, the effect of treatment pressure and temperature, treatment fluid concentration (SiO2 wt%) and
... Show MoreIn this work, a method for the simultaneous spectrophotometric determination of zinc which was precipitated into deionized water that is in a commercial distribution systems PVC pipe, is proposed using UV-VIS Spectrophotometer. The method based on the reaction between the analytes Zn2+ and 2-carboxy-2-hyroxy-5-sulfoformazylbenze (Zincon) at an absorption maximum of 620nm at pH 9-10. This ligand is selective reagent. Since the complex is colored (blue), its stoichiometry can be established using visible spectrometry to measure the absorbance of solutions of known composition. The stoichiometry of the complex was determined by Job’s method and molar ratio method and found to be 1:2 (M: L). A series of synthetic solution containing different
... Show MoreThe gas sensing properties of Co3O4 and Co3O4:Y nano structures were investigated. The films were synthesized using the hydrothermal method on a seeded layer. The XRD, SEM analysis and gas sensing properties were investigated for Co3O4 and Co3O4:Y thin films. XRD analysis shows that all films are polycrystalline in nature, having a cubic structure, and the crystallite size is (11.7)nm for cobalt oxide and (9.3)nm for the Co3O4:10%Y. The SEM analysis of thin films obviously indicates that Co3O4 possesses a nanosphere-like structure and a flower-like structure for Co3O4:Y.
The sen
... Show MoreWastewater treatment plants operators prefer to make adjustments because they are more cost effective, to use the existing tank instead of building new ones. In this case an imported materials would be used as bio-loads to increase biomass and thus maintain efficiency as the next organic loading increases.In the present study, a local substance "pumice stone" was used as a biological carrier in the aeration tank, and the experiments were carried out in five stages: without biological carriers, filling ratio of 4%,10%,20%, and25% with pumice stone, the maximum organic loading at each stage (1.1884, 1.2144, 1.9432, 2.7768, 3.3141)g BOD /l.d respectively.Other experiments were carried out to determine the best filling ratio, the SS remova
... Show More: Porous silicon (n-PS) films can be prepared by photoelectochemical etching (PECE) Silicon chips n - types with 15 (mA /cm2), in15 minutes etching time on the fabrication nano-sized pore arrangement. By using X-ray diffraction measurement and atomic power microscopy characteristics (AFM), PS was investigated. It was also evaluated the crystallites size from (XRD) for the PS nanoscale. The atomic force microscopy confirmed the nano-metric size chemical fictionalization through the electrochemical etching that was shown on the PS surface chemical composition. The atomic power microscopy checks showed the roughness of the silicon surface. It is also notified (TiO2) preparation nano-particles that were prepared by pulse laser eradication in e
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