Photoluminescence and Thermoluminescence Studies of Beta-Irradiated Ba3CdSi2O8:Tb3+ Phosphor for LED and Dosimetry Applications

The present work reports the preparation, characterization, and photoluminescence (PL) and thermoluminescence (TL) responses of Tb³⁺-doped Ba₃CdSi₂O₈ phosphors. X-ray diffraction analysis confirmed the consistency of the Tb³⁺-doped Ba₃CdSi₂O₈ samples with the PDF 00-028-0128 card structure. The TL glow curve of the material was examined at different dopant concentrations after irradiation with a ⁹⁰Sr/⁹⁰Y beta source. Among the samples, Ba₃CdSi₂O₈: 5% Tb³⁺ exhibited the highest TL intensity compared with the other concentrations. The glow curve deconvolution method was used to determine the number of peaks, trap structure, and kinetic parameters within the TL glow curve, yielding a figure of merit (FOM) value of 1.11. The PL spectra show that the 2.0%, 3.0%, 4.0%, 5.0%, and 6.0% mole Tb³⁺-doped Ba₃Cd (SiO₄)₂ phosphors capture excitation energy through the 4f-5d transitions of Tb³⁺ ions and emit light at 417, 440, 492, 552, 589, and 628 nm, corresponding to the 5D₃–7F₅, 5D₃–7F₄, 5D₄–7F₆, 5D₄–7F₅, 5D₄–7F₄, and 5D₄–7F₃ transitions, respectively.