In this work, high transparent TiO2 nano-crystallinethin films have been prepared by a simple sol–gel spin coating technique.The effect of the number of layers on physical properties of TiO2 thin films were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer, and four probes measurement.The XRD analysis confirms that TiO2 has anatase phase structure with preferred orientation of (101) direction, while the crystallite size values varied with the number of layers in the range of 16-19 nm. The films exhibit high optical transparency (>70%), reaching a maximum of 85% in the visible region with the red-shifted absorption edge, suggesting the films optical gap energy decreases with an increasing number of layers from 3.67 to 3.52 eV. However, the FTIR reflectance spectra show the existence of functional groups and chemical bonding.The films' electrical properties measurement indicated substantial enhancement in the resistivity with an increasing in the number of layers from3.3×105 to 2.15×106 Ω.cm. This study indicates that TiO2 films may be a potential candidate for technological applications as solar cells, photocatalysts, and gas sensors due to their desired structural, optical, and electrical properties.

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The aim of this work is to investigate the dependence of ZnS thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 mL/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of ZnS thin films was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical transmittance spectroscopy (UV–V) and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the (111) direction. The grain size values were calculated and found to be between 38 to 82 nm. SEM analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 eV. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 105 and 11 × 105 Ω·cm.

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