Preparation and optical properties of neodymium doped sol-gel glasses using trimethylphosphate as P₂O₅ precursor

The Nd³⁺ ions doped bulk glasses and thin films with the trimethylphosphate (TMP) as the precursor of P₂O₅ were prepared by the sol-gel technique. Their optical properties have been investigated. The Fourier Transform Infrared Spectra (FTIR) of Nd³⁺ doped SiO₂-TiO₂-P₂O₅ films have been measured to study the influence of P₂O₅ content in the removal of hydroxyl group. Fluorescence spectral results show stronger fluorescence intensity along with the narrowing of the emission bands due to the availability of the to-dopant P₂O₅ in the so-gel glasses compared with those of aluminum co-doped glasses. Our experimental results show that up to 6 wt% of Nd₂O₃ could be incorporated into the P₂O₅-SiO₂ glass matrix without significant fluorescence quenching effect due to the usage of the TMP as a precursor. We have also found that the hydroxyl groups could easily be removed at lower temperatures, as we increase the P₂O₅ content. It indicates that the P₂O₅ co-doping has a great potentiality in reducing the process temperature.