Substrate dipping in a composite sol-gel solution was used to prepare smooth and rough thin films of titanium dioxides (TiO2) on porous silicon (PS) and conductor glass. The fabrication process and optical measurements of these layers are presented. Sol-gel films were coated by dip-coating method on porous silicon layer. The characterizations of deposited layer were performed by spectral response, ellipsometry and spectrophotometry. The results show that the optical and electrical properties of the structures strongly depend on the deposition conditions of TiO2. In addition, the band gap energy Eg and refractive index of the structure can be easily varied depending on TiO2 thicknesses and calcination temperatures. Finally, the electrical and optical parameters show a promising result in solar cells application and photocatalytic activity.