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
Random laser gain media is synthesized with different types of dye at the same concentration (1×10-3 M) as an active material and silicon dioxide NPs (silica SiO2) as scatter centers through the Sol-Gel technique. The prepared samples are tested with UV–Vis spectroscopy, Fluorescence Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Diffraction (EDX). The end result demonstrates that doped dyes with silica nanoparticles at a concentration of 0.0016 mol/ml have lower absorbance and higher fluorescence spectra than pure dyes. FESEM scans revealed that the morphology of nanocrystalline silica is clusters of nano-sized spherical particles in the range (25-67) nm. It is con
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Density Functional Theory (DFT) with B3LYP hybrid exchange-correlation functional and 3-21G basis set and semi-empirical methods (PM3) were used to calculate the energies (total energy, binding energy (Eb), molecular orbital energy (EHOMO-ELUMO), heat of formation (?Hf)) and vibrational spectra for some Tellurium (IV) compounds containing cycloctadienyl group which can use as ligands with some transition metals or essential metals of periodic table at optimized geometrical structures.
The atomic properties have been studied for He-like ions (He atom, Li+, Be2+ and B3+ions). These properties included, the atomic form factor f(S), electron density at the nucleus , nuclear magnetic shielding constant and diamagnetic susceptibility ,which are very important in the study of physical properties of the atoms and ions. For these purpose two types of the wave functions applied are used, the Hartree-Fock (HF) waves function (uncorrelated) and the Configuration interaction (CI) wave function (correlated). All the results and the behaviors obtained in this work have been discussed, interpreted and compared with those previously obtained.
In this work, InSe thin films were deposited on glass substrates by thermal evaporation technique with a deposit rate of (2.5∓0.2) nm/sec. The thickness of the films was around (300∓10) nm, and the thin films were annealed at (100, 200 and 300)°C. The structural, morphology, and optical properties of Indium selenide thin films were studied using X-ray diffraction, Scanning Electron Microscope and UV–Visible spectrometry respectively. X-ray diffraction analyses showed that the as deposited thin films have amorphous structures. At annealing temperature of 100°C and 200°C, the films show enhanced crystalline nature, but at 300°C the film shows a polycrystalline structure with Rhombohedral phase with crystallites size of 17.459 nm. Th
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chloride or poluacrulic acid with different primary amines to mesuring==================================638one hundred three patinents with rheumatic symptoms were include in this study and their sera tested for
Background: Oral squamous cell carcinoma (OSCC) is the most prevalent malignant neoplasm of the oral cavity and constitutes a major health problem in developing. In the last 30 years, the 5-year survival rate of patients with oral SCC has not improved despite advance in diagnostic techniques. To improve early diagnosis for this deadly disease, new biological markers are needed. HOX genes encode homeodomain-containing transcription factors involved in the regulation of cellular proliferation and differentiation during embryogenesis. HOX gene expression has been described in several adult tissues, where they performed important roles in maintaining homeostasis. Few studies have suggested that HOXA1 plays a role in tumorigenesis. Besides bein
... Show MoreABSTRACT. A new three metal complexes of La(III), Ce(IV) and UO2(II) ions have been synthesized based on a Schiff base derived from the condensation of L-histidine and anisaldehyde. All prepared compounds were characterized by different spectroscopic techniques and Density-functional theory (DFT) calculations. The complexes were proposed to have an octahedral structure based on the investigated results. The optimized shape, numbering system, and dipole moment vector of Ligand and La, Ce, and UO2 (1:1) chelates were investigated. The Schiff base ligand and complexes exhibit moderate action against all of the bacteria tested, with P. aeruginosa, Klebsiella sp., and E. faecalis respectively being the order of inhibition.
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