Pure cadmium oxide films (CdO) and doped with zinc were prepared at different atomic ratios using a pulsed laser deposition technique using an ND-YAG laser from the targets of the pressed powder capsules. X-ray diffraction measurements showed a cubic-shaped of CdO structure. Another phase appeared, especially in high percentages of zinc, corresponding to the hexagonal structure of zinc. The degree of crystallinity, as well as the crystal size, increased with the increase of the zinc ratio for the used targets. The atomic force microscopy measurements showed that increasing the dopant percentage leads to an increase in the size of the nanoparticles, the particle size distribution was irregular and wide, in addition, to increase the surface roughness of the nanoparticles. An increase in the zinc ratio also led to a decrease in the energy gap. While the Hall effect measuring showed an increase in the concentration of charge carriers and a decrease in their mobility with increasing the doping ratio.
The effect of annealing temperature (Ta) on the electrical properties like ,D.C electrical conductivity (σ DC), activation energy (Ea),A.C conductivity σa.c ,real and imaginary (ε1,ε2) of dielectric constants ,relaxation time (τ) has been measured of ZnS thin films (350 nm) in thickness which were prepared at room temperature (R.T) using thermal evaporation under vacuum . The results showed that σD.C increases while the activation energy values(Ea) decreases with increasing of annealing temperature.(Ta) from 303- 423 K .
The density of charge carriers (nH) and Hall mobility (μH) increases also with increasing of annealing temperature Hall effect measurements showed that ZnS films were n-type converted to p-type at high annealin
Titanium dioxide (TiO2) Nano powder has been synthesized by hydrothermal method. The reaction took place between titanium tetrachloride (TiCI4) and mixture solution consisted of deionized water and ethanol, in the ratio (3:7) respectively. Structure and surface morphology of TiO2 Nano powder at different annealing temperatures in the range 200-800°C for 120 min were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM), Scanning Electron Microscopy (SEM), FT-IR and UV/visible spectroscopy measurements. The results show that with an increase in annealing temperature, the value of the intensity of (110) peak for rutile phase increases while the value of the full-width at half maximum (FWHM) decreases, and the band gap de
... Show MoreIn this research a computational simulation has been carried out on the design and properties of the electrostatic mirror and a mathematical expression has been suggested to represent the axial potential of an electrostatic mirror. The electron beam path using the Bimurzaev technique had been investigated as mirror trajectory with the aid of Runge – Kutta method. The spherical and chromatic aberration coefficients of mirror has computed and normalized in terms of the focal length. The choice of the mirror depends on the operational requirements. The Electrode shape of mirror two electrodes has been determined by using package SIMION computer program. Computations have shown that the suggested potentials giv
... Show MoreAlloy of (HgTe) has been prepared succesful in evacuated qurtz ampoule at pressure 4×10-5torr, and melting temperature equal to 823K for five days. Thin films of HgTe of thickness 1μm were deposited on NaCl crystal by thermal evaporation technique at room temperature under vacuum about 4×10-5torr as well as investiagtion in the optical porperties included (absorption coefficient , energy gap) of HgTe films and The optical measurements showed that HgTe film has direct energy gap equal to 0.05 eV. The optical constants (n, k, εr, εi) have been measured over will range (6-28)μm.
The aim of the present research is concerned with study the effect of UV radiation on the optical properties at wavelengths 254, 365 nm of pure PC and anthracene doping PC films prepared using the cast method for different doping ratio 10-60 mL. Films of pure PC and anthracene doping PC were aged under UV radiation for periods of up to 360 h. It found that the effect of UV radiation at wavelength 254 nm on the optical properties is great than the effect of UV radiation at wavelength 365 nm. Also, it found that the optical energy gap of pure PC and anthracene doping PC films is stable against radiation.
A polycrystalline CdTe film has been prepared by thermal evaporation technique on glass substrate at substrate temperature 423 K with 1.0 m thicknesses. The film was heated at various annealing temperature under vacuum (Ta =473, 523 and K). Some of physical properties of prepared films such as structural and optical properties were investigated. The patterns of X-ray diffraction analysis showed that the structure of CdTe powder and all films were polycrystalline and consist of a mixture of cubic and hexagonal phases and preferred orientation at (111) direction.
The optical measurements showed that un annealed and annealed CdTe films had direct energy gap (Eg). The Eg increased with increasing Ta. The refractive index and the real p
The Influence of annealing temperature on the optical properties of (CuInSe2) thin films was studied. Thermal evaporation in vacuum technique has been used for films deposited on glass substrates, these films were annealed in vacuum at (100C°, 200C°) for (2 hours). The optical properties were studied in the range (300-900) nm. The obtained results revealed a reduction in energy band gap with annealing temperature . optical parameters such as reflectance, refractive index, extinction coefficient, real and imaginary parts of the dielectric constant, skin depth and optical conductivity are investigated before and after annealing. It was found that all these parameters were affected by annealing temperature.