Titanium Dioxide Thin Films Prepared on Different Substrates by Sol–Gel Process: Optical and Morphological Properties

Abstract In this study, sol-gel TiO 2 thin films were obtained by spin coating on Si, glass and ITO substrates. They were characterized using Field emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FTIR) spectroscopy and Ultraviolet – Visible (UV-VIS) spectroscopy. The impact of the film thickness (different number of layers), annealing temperatures (300, 400 and 500°C) and the type of substrates on the morphology, optical transmittance and vibrational properties were investigated. The work function (WF) of the samples was also determined. TiO 2 films on glass substrates revealed a decrease of the film transparency with increasing the film thickness and after annealing at 400 and 500°C. TiO 2 films obtained on ITO substrates exhibited very high transmittance in the visible spectral range up to 85%, despite the number of layers and the thermal treatments. FESEM study showed very uniform, smooth surface with small grained structure.