Aluminum doped zinc selenide ZnSe/n-Si thin films of (250∓20 nm) thickness with (0.01, 0.02 and 0.03), are depositing on the two type of substrate (glass and n-Si) to manufacture (ZnSe/n-Si) solar cell through using thermal vacuum evaporation procedure. physical and optoelectronic properties were examined for the samples. X-Ray and AFM techniques are using to study the structure properties. The energy band gap of as-deposited ZnSe thin films for changed dopant ratio were ranging from (2.6-2.68 eV). The results of Hall effect show that pure and doping films were (p-type), and the concentration carriers and the carriers mobility increases with increase Al-dopant ratio. The (C-V) have shown that the heterojunction were of abrupt type. In addition, the I-V characteristics of ZnSe /Si heterojunctions show the forward dark current varies with applied voltage, besides the saturation current and the ideality factor are determined under different doping percentage. Also, the (I– V) characteristic for ZnSe/Si heterojunction show that the forward current at dark varies with applied voltage and the Isc and Voc have been studied. The photoelectric properties designated an increase light current of hetero junctions with cumulative Al-dopant, and I-V characteristics under illumination showed that the heterojunction (ZnSe: Al (0. 3%)/Si) have a high efficiency.
This research deals with study of the effect of additives on rheological properties (yield point, plastic viscosity ,and apparent viscosity) of emulsions. Twenty seven emulsion samples were prepared; all emulsions in this investigation are invert emulsions when water droplets are dispersed in diesel oil. The resulting emulsions are called water-in-oil (W/O) emulsions. The rheological properties of these emulsions were investigated using a couett coaxial cylinder rotational viscometer (Fann-VG model 35 A), by measuring shear stress versus shear rate. It was found that the effect of additives on rheological properties of emulsions as follow: the increase in the concentration of asphaltic material tends to increase the rheological propertie
... Show MoreA quantum mechanical description of the dynamics of non-adiabatic electron transfer in metal/semiconductor interfaces can be achieved using simplified models of the system. For this system we can suppose two localized quantum states donor state |D› and acceptor state |A› respectively. Expression of rate constant of electron transfer for metal/semiconductor system derived upon quantum mechanical model and perturbation theory for transition between |ð·âŒª and |ð´âŒª state when the coupling matrix element coefficient is smaller than 0.025eV. The rate of electron transfer for Au/ ZnSe and Au/ZnS interface systems is evaluated with orientation free energy using a Matlap program. The
... Show MoreA progression of Polyaniline (PANI) and Titanium dioxide (TiO2) nanoparticles (NPs) were prepared by an in-situ polymerization strategy within the sight of TiO2 NPs. The subsequent nanocomposites were analyzed using Fourier-transform infrared spectra (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Analysis (EDX) taken for the prepared samples. PANI/TiO2 nanocomposites were prepared by various compound materials (with H2SO4 0.3 M and without it, to compare the outcome of it) by the compound oxidation technique using ammonium persulfate (APS) as oxidant within the sight of ultrafine grade powder of TiO2 cooled in an ice bath.
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Different percents(1.0,2.5,5.0 and 10)wt%of MgO powders were added to ZnO powder to study their effects on the physical properties of ZnO.Density, porpsity and water absorption of ZnO were decreased as MgO weigth percentage content increased. The values of vickers hardneess have double values especially at 1.0 wt % of MgO.
Schmidt Cassegrain spider obscuration telescope (SCT) is one of the types of observations operating with a concave mirror. It combines several lenses and mirrors working together as an optical system. The light rays fall into the tube from the main mirror and gather on another smaller mirror called a secondary mirror. Unlike the formation of Newton's telescope, no light is made from the secondary mirror out the side of the tube but is directed to the middle of the main mirror. There is an opening in the middle of the main mirror so the light beam can go out and direct the vision lens system. The secondary mirror is located in the middle of a glass slice and is installed by thin carriers. The function of this board is to correct the portr
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In this research we prepared thin films from pure polymer (polyvinyl alcohol PVA )and doped with CuO with concentration 8% ,and Fe2Cl3 at different concentrations (1,5,8)%.This films were prepared by casting method and placed in Britidish (4cm diameter )with thickness(200±5)μm.Through the investigation of(X-ray )diffraction it is found all that the samples have polycrystalline structure .Also we measurement the optical properties from this films such as absorption ,transmittion spectra ,absorption coefficient ,energy gap ,extinction coefficient ,refraction index ,finesse coefficient ,the dielectric constant with two parts the real and the imaginary and the optical conductivity .
In this research, A thin film of Rhodamine B dye and TiO2 Nanoparticles doped in PMMA Polymer has been prepared by a casting method. The sample was spectrum absorption by UV-Vis. The nonlinear optical properties were measured by Z- scan technique using Nd:YAG laser with (1064 nm) wavelength. The nonlinear refractive index (n2) and nonlinear absorption coefficient (β) were estimated for the thin film for different energies of the laser, n2 and β were decreased with increasing intensity of incident laser beam. Also, the type of β was two-photon absorption and n2 negative nonlinear reflective.
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