Abstract. In this work, Bi2O3 was deposited as a thin film of different thickness (400, 500, and 600 ±20 nm) by using thermal oxidation at 573 K with ambient oxygen of evaporated bismuth (Bi) thin films in a vacuum on glass substrate and on Si wafer to produce n-Bi2O3/p-Si heterojunction. The effect of thickness on the structural, electrical, surface and optical properties of Bi2O3 thin films was studied. XRD analysis reveals that all the as deposited Bi2O3 films show polycrystalline tetragonal structure, with preferential orientation in the (201) direction, without any change in structure due to increase of film thickness. AFM and SEM images are used to investigate the influences of film thickness on surface properties. The optical measurement were taken for the wave length range (400-1100) nm showed that the nature of the optical transition has been direct allowed with average band gap energies varies in the range of (2.9-2.25) eV with change thickness parameter. The extent and nature of transmittance, absorbance, reflectance and optimized band gap of the material assure to utilize it for photovoltaic applications. Hall measurements showed that all the films are n-type. The electrical properties of n-Bi2O3/p-Si heterojunction (HJ) were obtained by I-V (dark and illuminated) and C-V measurement at frequency (10 MHz) at different thickness. The ideality factor saturation current density, depletion width, built-in potential and carrier concentration are characterized under different thickness. The results show these HJ were of abrupt type. The photovoltaic measurements short-circuit current density, open-circuit voltage, fill factor and efficiencies are determined for all samples. Finally thermal oxidation allowed fabrication n-Bi2O3/p-Si heterojunction with different thickness for solar cell application.
This work involves synthesis of novel Schiff bases derivatives contining isoxazoline or pyrazoline units starting with chalcons . 4-Aminoacetophenone was reacted with 3-nitrobenzaldehyde in basic medium giving chalcone [I] by claisen-schemidt reaction. The chalcone [I] was reacted with hydroxylamine hydrochloride giving isoxazoline [II] in basic medium. The chalcone [I] could also react with hydrazitne hydrate to give pyrazoline [III] . The novel Schiff bases with structural formula [IV] and [V] were prepared by the reaction of amino compounds ; isoxazoline [II] and pyrazolines [III] with p-substituted aldehydes or p-subsituted ketones, respectively in dry benzene using drops of glacial acetic acid as a cat
... Show MoreMercury-lead-antimony based superconductors with the formula Hg0.5 Pb0.5xSbxBa2Ca2Cu3O8+δ (x=0, 0.10 and 0.15) have been prepared by useing three step solid state reaction processes. Electrical resistivity, using four probe technique, is used to find the transition temperature Tc. It is found from that sample Hg0.5 Pb0.5Ba2Ca2Cu3O8.437 is semiconductor , sample Hg0.5 Pb0.4Sb0.1Ba2Ca2Cu3O8.353 is normal state with metallic behaviors, while sample Hg0.5 Pb0.35Sb0.15Ba2Ca2Cu3O8.233 is superconducting state with critical transition temperature (Tc) is 126K. X-ray diffraction (XRD) analysis showed a tetragonal structure with decrease in the c-axis lattice constant for the samples doped with Sb as compared with these which have no Sb
... Show MoreSolvent- free thermal heating, one-pot condensation of acetophenone, ethyl cyanoacetate or malononitrle and substituted Aromatic aldehyde, ammonium acetate give, 2oxo-3-cyano-4-substituted Aryl-6-phenyl pyridine [I]a-h , or 2-amino-3-cyano-4-substituted Aryl-6-phenyl pyridine derivatives[II]a-f , respectively. Treatment of compounds 2-oxo-3-cyano-4-substituted Aryl-6-phenyl pyridine with phosphorous penta sulphide (P2S5), give 2-thioxo-3-cyano-4-substituted Aryl-6-phenyl pyridine derivatives[III]a-c . All prepared compounds
... Show MoreFive novel nickel, iron, cobalt, copper, and mercury complexes were synthesized from tetraazamacrocyclic Schiff base ligand (L), which were derived from 3-(4-(dimethyl amino) benzylidene) pentane-2,4-dione and 1,2- diaminocyclohexane in a 2:2 molar ratio. Many physico-chemical and spectroscopic techniques, including melting point, 1HNMR, 13CNMR, elemental analysis, molar conductance, magnetic susceptibility, UV-Vis, FT-IR, and thermogravimetric analysis (TGA), were used to characterize the Schiff base ligand and all metal complexes. The octahedral geometry of all the complexes [MLCl2] is confirmed by spectroscopic analyses. All substances' biological properties, such as their in vitro antioxidant activity or level of free radical scavenging
... Show More4-Thiazolidinone were synthesized by three steps,the reaction of ansoyl chloride with 4hydroxy benzaldehyde to give 4-(4`-methoxy benzoyloxy) benzaldehyde[I].The reaction of later compound with thiosemicarbazideled to formation thiosemicarbazon [II] and the reacted thiosemicarbazone with chloro acetic acid in CH3CO2Na medium to yield 4- thiazelidinone compound[III].The 4-thiazolidinone [III]was used as a key intermediates to synthesis new compounds, compound[IV] synthesized from the reaction [III] with acetic anhydride, while the reaction of compound [III] with amines to yield azo compound[V]a,b,c. The azo compound reacted with benzoyl chloride or anisole chloride in basic medium to get a new esters compound[VI]a,b. Also, synthesi
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New Schiff bases derivatives [IV]a-e is prepared via condensation of Derythroascorbic acid with p-substituted aldehydes in dry benzene. To obtain these derivatives, the 5,6-O-isopropylidene-L-ascorbic acid[I] was chosen as starting material, compound prepared from the reaction of L-ascorbic acid as starting material. Compound[I] was prepared from the reaction of L-ascorbic acid with dry acetone in the presence of hydrogen chloride. The esterification of hydroxyl groups at C-2 and C-3 positions with excess ofethyl α –chloroacetate in the presence of sodium acetate produce acorresebonding ester [II] , which was condensed with hydrazine hydrate to give new hydrazide [III] . The new Schiff bases [IV]a-e were synthesized by reaction of acid h
... Show MoreThis study is concerned with the effect of adding two kinds of ceramic materials on the mechanical properties of (Al-7%Si- 0.3%Mg) alloy, which are zirconia with particle size (20μm > P.S ≥ 0.1μm) and alumina with particle size (20μm > P.S ≥ 0.1μm) and adding them to the alloy with weight ratios (0.2, 0.4, 0.6, 0.8 and 1%). Stirring casting method has been used to make composite material by using vortex technique which is used to pull the particles to inside the melted metals and distributed them homogenously.
After that solution treatment was done to the samples at (520ºC) and artificial ageing at (170ºC) in different times, it has been noticed that the values of hardness is increased with the aging time of the o
... Show MoreThe organation ⁄monomer N-naphthylacrylamide (NAA) was prepared; subsequently the synthesized monomer was successfully copolymerized with acrylicacid (AA) and methylacrylate (MA) by free radical technique using dry benzene as solvent and benzoyl peroxide (BPO) as initiator. The overall conversion was kept low (≤ 10% wt/wt) for all studies copolymers samples. The synthesized monomer and copolymers were characterized using Fourier transform infrared spectroscopy (FT-IR), and their thermal properties were studied by DSC and TGA. The copolymers compositions were determined by elemental analysis. Kelen-Tudes and Finmman-Ross graphical procedures were employed to determine
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Nuclear emission rates for nucleon-induced reactions are theoretically calculated based on the one-component exciton model that uses state density with non-Equidistance Spacing Model (non-ESM). Fair comparison is made from different state density values that assumed various degrees of approximation formulae, beside the zeroth-order formula corresponding to the ESM. Calculations were made for 96Mo nucleus subjected to (N,N) reaction at Emax=50 MeV. The results showed that the non-ESM treatment for the state density will significantly improve the emission rates calculated for various exciton configurations. Three terms might suffice a proper calculation, but the results kept changing even for ten terms. However, five terms is found to give
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