Ultraviolet and visible reflective TiO2/SiO2 thin films on silicon using sol-gel spin coater

TiO2/SiO2 alternative thin films (stacks) were deposited on silicon substrates using sol-gel spin-coating techniques. The prepared samples had their corresponding optical properties analyzed by UV-Visible spectrophotometry (UV-Vis), X-ray diffractometry (XRD), a surface profilometer, and Raman spectroscopy. The optical and crystallization properties of thin films were varied and compared by changing the number of stacks. UV-Vis spectrum showed high reflectance and shifting towards the infrared region with effect of increased TiO2/SiO2 stacks. XRD spectra confirmed the existence of anatase TiO2 and SiO2 diffraction peaks. The multilayer film thickness was calculated at 109 and 151 nm at two and four stacks by a surface profilometer. The Raman spectra confirmed the Si-O-Si and TiO2 stretching modes at 2600, 980, and 519 cm. This investigation reveals the promising and effective UV-Visible reflective property of alternative TiO2/SiO2 thin films on a silicon substrate.