The effect of sputtering current that flow in a carbon rod on the structural and transport properties of Si-C junction is studied. Si-C junction is fabricated by plasma sputtering in Argon gas atmosphere without catalysts with thickness of 20, 40 and 60 nm. Images of the specimen by scanning electron microscope (SEM) and atomic force microscope (AFM) show that the carbon layer is as carbon nanotubes with diameters about 20-30 nm. X-ray and Raman spectrums show peak characteristics of the carbon nanotubes, the G and D bands appear for all thicknesses indicating free of defect carbon nanotubes. Two parameters about the thickness of the carbon layer and the sputtering current for different thicknesses and currents were studied. Nanotubes evidence was clear. We noticed that the sputtering current and thickness of layers affect the structure of CNT layer leading to the formation of grains. Increasing plasma current led to decrease grain formation however increasing thickness ends to increase grain size; moreover it led to amorphous structure formation and this was proved through X-ray, Raman spectra and AFM images.

Chemical bath deposition was used to prepare thin films of ZnTe. The density of compounds (0.5-2) ml in 50 ml of distilled water, the precipitation time (10-80 min), and the solution temperature during the precipitation process (15-85 C) have been changed during the preparation of the ZnTe thin films to get the optimal deposition conditions of a semiconductor. The effect of these parameters has been determined by studying the optical properties of the films which included the transmittance and absorbance as a function of the wavelength and energy gap. The energy gap remains constant at about 2.7 eV over all precipitation times for each density of compound. We have also found that the energy gap of the films decreases with increasing solution temperature, reaching approximately 2.9-3eV at 15 C and decreasing to 2.4 eV at 85 C.

Thin film of ZnTe have been synthesized using chemical bath method for different periods (30, 50 and 70 min), the surfaces of these films were imaged using a scanning electron microscope, and the amount of each element of zinc and tellurium was determined in each film depending on the deposition period. The study of optical properties included measuring the transmittance and absorbance with wavelength, we used these measurements to calculate the energy gap and its variation with the deposition time.

The research studies the effect of the distance between the sample and the plasma sputtering source on the properties of the junction (silicon wafer-carbon nanotubes). The silicon wafer is fixed at (near, medium and far distances from the plasma source which is in the form of high purity graphite rod heated electrically). For the three cases, thickness of the sample is constant (20 nm). The samples were studied by scanning electron (SEM) and atomic force microscopes (AFM), X-ray and Raman spectra. For optimum distances the carbon layer is in the form of multi wall carbon nanotube (MWCNT). SEM images shows no formation of CNT on the Si wafer for near distance, which is consistent with the AFM images, X-ray and Raman spectrograms and no existence of characteristics (002) peaks whereas it appears for medium and longer distances, and by experience the optimum distance was found. This means that at closer distance high energy and high intensity plasma particles prevent the formation of CNT. This effect decreases with increasing distance of substrate from the graphite rod.

Thin films of CdS have been prepared on glass substrates by the chemical spray pyrolysis method at 250oC from solutions including different concentrations of Na2S (0.2 g and 0.4 g). The films were examined using SEM, an X-ray spectrometer, and a UV-Visible spectrometer. The SEM images and X-ray spectrum show that the films were amorphous, and the grain size varied with Na2S concentration. The optical properties and optical constants also varied clearly with Na2S concentration; in addition, the energy gap changed from 2.3 eV to 2.4 eV for both films.

Nano porous silicon was achieved by electrochemical etching technique of current density 20 mA/cm 2 , 25% HF and etching time 15min. Carbon Nano layers have been deposited on PSi substrate by PECVD. XRD spectrum show that porous silicon has crystalline phase and becomes very broad after etching time, in addition, XRD spectrum for carbon layers show several peaks between (2θ=28.25-28.75) which belong to carbon nanotube and these peaks intensity increases with increasing of carbon thickness. Raman spectrum illustrates that peak position was at 516.32nm for porous silicon prepared at etching time 15 min.

Plasma sputtering was used to deposit carbon layer from pure graphite with thicknesses (20, 54, 63 nm) on a p-type silicon wafer substrate for the preparation of a Si-CNT (Silicon-Carbon Nano Tubes) junction without any catalyst. The I-V characteristics of the junction were found to be similar to that of the diode, which confirm that the carbon layer or, in other words, that the carbon nanotubes are acting as an n-type semiconductor. The effect of heat and light illumination on the I-V characteristics is studied. At temperatures (32, 40, 50 and 60 o C), the I-V characteristics shows increase in conductivity with increasing the temperature for a certain thickness. The effect of light on I-V characteristics has also been studied showing an increase in current flow, the effect of both heat and light illumination is more pronounced at low values of the thickness of the CNT layer due to their low resistivity.

Chemical bath deposition technique was used to deposit nickle oxide , Copper oxide and their mixture. The optical gap properties of both compounds and mixture were measured , the transmittance, absorbance, reflectance, extinction and refractive index have been calculated with in the wavelength range (320-900 nm).