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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.

Transparent conducting n-type SnO2 semiconductor films were fabricated by employing an inexpensive, simplified spray ultrasonic technique using an ultrasonic generator at deferent substrate temperatures (300, 350, 400, 450 and 500 °C). The structural studies reveal that the SnO2 films are polycrystalline at 350, 400, 450, 500 °C with preferential orientation along the (200) and (101) planes, and amorphous at 300 °C. The crystallite size of the films was found to be in the range of 20.9–72.2 nm. The optical transmittance in the visible range and the optical band gap are 80% and 3.9 eV respectively. The films thicknesses were varied between 466 and 1840 nm. The resistivity was found between 1.6 and 4 × 10−2 Ω·cm. This simplified ultrasonic spray technique may be considered as a promising alternative to a conventional spray for the massive production of economic SnO2 films for solar cells, sensors and opto-electronic applications.

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