Engineering trap dynamics in Ba₂ZnSi₂O₇ phosphors: a study on rare-earth co-doping for efficient TL dosimetry

The present study investigates the thermoluminescence properties of Ba₂ZnSi₂O₇ phosphors co-doped with rare-earth ions (Dy³⁺, Sm³⁺, and Tb³⁺) for radiation dosimetry applications. The phosphors were synthesized with varying dopant concentrations, and their TL glow curves were recorded under γ-irradiation over a wide dose range. The glow curves exhibited well-defined peaks, indicating the presence of discrete trapping centers. The TL intensity showed a strong dependence on dopant concentration, with optimal compositions displaying maximum emission, while higher concentrations led to concentration quenching. Dose-response studies revealed a linear increase in TL intensity within specific dose regions, followed by saturation at higher doses due to trap filling. Sensitivity and minimum detectable dose were evaluated, demonstrating that the phosphors possess good detection capability across low to high dose ranges. The trapping parameters, including activation energy, frequency factor, and trap lifetime, were determined using Computerized Glow Curve Deconvolution, Chen's peak shape method, and the initial rise method. The calculated activation energies ∼1-1.8 eV indicate the presence of stable deep traps. The consistency among different analytical methods confirms the reliability of the results. Overall, the study highlights that Ba₂ZnSi₂O₇ based phosphors are promising materials for radiation dosimetry, with tuneable properties suitable for radiation detection applications.