Thermal, Optical, and Structural Properties of Eu3+-Doped TiO2 Nanophosphors

Abstract

Eu³⁺-doped TiO₂ nanophosphors were synthesized using the co-precipitation method and characterized for structural, optical, and thermoluminescent (TL) properties. X-ray diffraction (XRD) analysis confirmed the anatase phase with crystallite sizes ranging from 19.47 to 28.05 nm. UV–Vis spectroscopy revealed a redshift on doping Eu³⁺ which causes a decrease in the optical band gap from 3.73 eV (pure TiO₂) to 3.44 eV (Eu-doped samples) as defect states introduced by europium ions. Raman and FTIR spectroscopy confirmed the structural integrity and vibrational modifications induced by Eu³⁺ doping. Thermoluminescence studies exhibited a prominent glow peak at 287 °C for TiO₂ doped with 3 mol % Eu³⁺, with quenching at higher doping levels due to the saturation of trapping centres. The activation energy of TL glow peaks is calculated using peak shape methods, ranging from 0.732 to 0.818 eV, indicating the presence of deep trap levels. The frequency factor varied between 2.78 × 10⁷ s⁻¹ and 1.68 × 10⁸ s⁻¹, suggesting a thermally stable trapping mechanism. The relatively low activation energy highlights the potential of Eu³⁺-doped TiO₂ as a rapid-response sensor material, suitable for radiation dosimetry and optoelectronic applications. These findings demonstrate that controlled Eu³⁺ doping can enhance the luminescence efficiency and thermal stability of TiO₂ nanophosphors, making them promising candidates for advanced sensing and display application.