Photoluminescence and thermal stability of Tb3+-doped Gd2O3 nanoparticles embedded in SiO2 host matrix

Terbium doped SiO2-Gd2O3 materials were obtained by a sol-gel process and heat-treated at 1000 °C. The effect of Tb3+concentration on structural, optical and photoluminescent properties of materials are reported here. FT-IR indicated the presence of Gd2O3 and SiO2 in the composition of materials. XRD showed the formation of the Gd2O3 cubic phase without the presence of phase impurities, and lattice parameter calculations indicated the effective inclusion of Tb3+ in Gd2O3 crystalline structure. SEM analysis revealed spherical particles of Gd2O3 and TEM confirmed that these particles are included in the amorphous SiO2. Excitation spectra show bands in the UV-region at characteristic wavelengths of the Gd2O3 host absorption. Emission spectra were collected by changing the excitation, and the intensity shows dependence on the UV photon energy. Tb3+-doped Gd2O3 grown into SiO2 showed higher Tb3+ lifetimes which are ideal for photonic applications. The temperature significantly influenced the luminescence of the materials, with chromaticity changing from green to blue region. The activation energy for thermal quenching (Ea) was determined by an Arrhenius methodology and the material shows a high thermal stability (Ea for thermal quenching = 0.378 eV). [Display omitted] •The work reports the grown of Tb3+-doped Gd2O3 nanoparticles into SiO2 via sol-gel.•The effects of Tb3+ concentration in the photoluminescence are discussed.•Thermal parameters reveal good stability, assigned to encapsulating by SiO2.•Material shows good thermal response, applicable in thermometric devices.