FTIR and XPS investigation of Er-doped SiO2–TiO2 films

The ultraviolet photo-induced chemical vapour deposition (UV-photo-CVD) process is a highly flexible and efficient technique for fabrication of thin oxide films. We report in this work the deposition of Er-doped SiO2–TiO2 thin films using UV-photo-CVD at temperatures between 350 and 500 °C. Erbium isopropoxide, titanium tetraisopropoxide (TTIP) and tetraethoxysilane (TEOS) are used as precursors. The films are measured to be around 20–100 nm in thickness with refractive indices from 1.60 to 1.90. The chemical, optical, microstructural and spectroscopic properties of the films have been investigated by Fourier transform infrared spectroscopy (FTIR), ellipsometry, photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). High quality as-deposited films with various Ti/Si ratios and low carbon contents have been confirmed by XPS measurement. Er-doped titania–silica films were produced by UV-photo-CVD and effect of thermal and UV annealing on these films has also been studied.