Etude des propriétés optique des couches minces de tio-sio

Abstract

Alternating thin films of titanium dioxide (TiO2) and silicon dioxide (SiO2) are extremely important in various technological and industrial fields due to their synergistic properties and complementary applications. Our thesis aims to explore the structural, morphological, and optical properties of samples composed of thin films of titanium dioxide and silicon dioxide, as well as their layering. These films are prepared using the Sol-Gel method with dip-coating, followed by annealing at 400°C. Our primary objective is to characterize these samples to identify those exhibiting semi-reflective properties. The results indicate that FTIR spectroscopy confirms the presence of vibrations from Si-O-Si, Si-OH, and Ti-O bonds in a stack of SiO2 and TiO2 layers. Atomic force microscopy confirms that SiO2 significantly influences TiO2, reducing roughness and smoothing the surface compared to TiO2 layers alone. Additionally, UV-visible spectroscopy shows that alternating layers of TiO2 and SiO2 are transparent in the visible spectrum but opaque in the ultraviolet range. However, it is not feasible to calculate the thickness and refractive index for these alternating layers. To characterize the transmission and reflection of our samples, we set up an optical assembly with optical components, varying the angle of incidence at a wavelength of 638.2 nm. We observed that the sample composed of a single layer of SiO2 and two layers of TiO2 exhibits semi-reflective properties.