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
Attention increased to the topic of academic accreditation by the university as a modern philosophy by which to improve its performance and provide high-quality education. Universities and colleges in general and Iraqi universities and colleges in particular have begun interest in accreditation and desire to get it. So starting from the pursuit of the Administration and Economics College / Baghdad University in obtaining accreditation of Association to Advance Collegiate Schools of Business (AACSB) The research is present which aims to determine the level of application (AACSB) International standards at the College of Administration and Economics / Baghdad University in preparation to get its accreditation in the future. Researc
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Nowadays, the worldwide issue of the environment occupies the minds not only of ecological experts and politicians but also is addressed in cultural fields and literature in particular. The conceptualization of ecocriticism, whether in the ecological field or cultural studies, has come as a response to the increasing public awareness of numerous environmental crises. Most ecocritics regard John Clare (1793-1864) as a 'proto-ecological' British poet since his poetry incorporates ecological issues which were not then categorized as they are now. The study offers a precise illustration of ecocriticism coupled with a number of the most significant ecological concepts proven in selected poems by John Clare. The ecocritical reading of Clare's po
... Show Moregenerator the metal conductor is replaced by conducting gas plasma.
The purpose of this research is to study the quality of scientific research at the University of Baghdad in light of scientific piracy and plagiarism of research and results and attribute it to others intentionally or unintentionally. Proactive writing such as stealing ideas or synthesizing the results of one another over others and its negative impact on the quality of scientific outputs and the reputation of educational organizations through an exploratory study in the faculties of the University of Baghdad, scientific and humanitarian. As for the aims of the study, it was determined by determining the negative impact of piracy on scientific research. A Likert five-point scale was used in this research. The research community c
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The research aims at the possibility of measuring the technical and scale efficiency (SE) of the departments of the College of Administration and Economics at the University of Baghdad for a period lasting 8 years, from the academic year 2013-2014 to 2018-2019 using the method of Applied Data Analysis with an input and output orientation to maintain the distinguished competitive position and try to identify weaknesses in performance and address them. Nevertheless, the research problem lies in diagnosing the most acceptable specializations in the labor market and determining the reasons for students’ reluctance to enter some departments. Furthermore, the (Win4DEAp) program was used to measure technical and scale efficiency (SE) and rely on
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Background: Sialosis described as a specific consequence of diabetes. In diabetic sialosis, the increased volume of the glands is due to the infiltration of adipose in the parenchyma. The B-scan ultrasonography is a generally accepted tool for determining parotid gland enlargement. Oral health is, to a greater extent, dependent on quality and quantity of saliva, both of which may be altered in diabetics. This study was established to detect the enlargement of parotid gland in diabetic patient and study the changes in physical properties of saliva and its relation with the salivary gland enlargement. Subjects, Materials and Methods: A cross-sectional study with highly specified criteria with ages ranged (20-65) years, male and female subject
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Abstract
This study investigates the mechanical compression properties of tin-lead and lead-free alloy spherical balls, using more than 500 samples to identify statistical variability in the properties in each alloy. Isothermal aging was done to study and compare the aging effect on the microstructure and properties.
The results showed significant elastic and plastic anisotropy of tin phase in lead-free tin based solder and that was compared with simulation using a Crystal Plasticity Finite Element (CPEF) method that has the anisotropy of Sn installed. The results and experiments were in good agreement, indicating the range of values expected with anisotropic properties.
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... Show MoreThe corona virus epidemic outbreak has urged an extreme worldwide effort for re‐purposing obtainable approved medications for its treatment. In this review, we're focusing on the chemicals properties andpharmacologicaleffectiveness of medicationsofsmallmolecule that are presently being evaluated in clinical trials for the management of corona virus (COVID‐19). The current review sheds light on a number of drugs that have been diagnosed to treat COVID‐19 and their biological effects.