Optical properties of rhodamine 6G-doped TiO₂ sol-gel films

The optical properties of titania (TiO₂) thin films prepared by the sol-gel process and doped with rhodamine 6G were studied by Photoacoustic Spectroscopy. Rhodamine 6G-doping was achieved by adding 0.01%, 0.02%, 0.05% y 0.1% mol rhodamine to a solution that contained titanium isopropoxide as precursor. Two absorption regions were distinguished in the absorption spectrum of a typical rhodamine 6G-doped TiO₂ film. A shift of these bands occured as a function of rhodamine 6G-doping concentration. In addition, the optical absorption and band gap energy for rutile-phase TiO₂ films were calculated, employing the full-potential linearized augmented plane wave method. A comparison of these calculations with experimental data of TiO ₂ films prepared by sol-gel at room temperature was performed.