Structural and thermoluminescence attributes of Yb3+:Li2B4O7 synthesized through facile microwave-ignited combustion route

Herein, we investigate the structural and defect attributes of Li 2 B 4 O 7 :Yb 3+ , synthesized for the first-time by facile microwave-ignited combustion route, highlighting its potential in high-range dosimetry. Both pure and Yb 3+ -doped samples exhibit water-equivalent response across the 0.1-10 MeV energy range. Li 2 B 4 O 7 and Yb 3+ -doped samples crystallized in the tetragonal phase. The incorporation of Yb 3+ -ions has led to lattice expansion. X-ray scattered electron density confirms ionic and covalent nature of Li-O and B-O bonds respectively. Morphological study displays uniformly distributed spherical particles. Li 2 B 4 O 7 exhibits excellent UV-Visible (200-800 nm) transparency, with direct bandgap of 5.32 eV, while doping causes a variation in the bandgap within 5.08-5.30 eV. Yb 3+ -doped samples show two broad glow peaks after γ-ray irradiation. Glow peak at 648 K exhibits linear TL response in the 100-5000 Gy dose-range, whereas low temperature glow peak displays sublinear nature beyond 1000 Gy. T m -T stop and deconvoluted analysis identified six discrete trap-levels with frequency factor of the order of 10 9 s −1 . Urbach's coefficient is estimated to be 25.51. The activation energies of the traps are found to be 0.78 ± 0.01, 0.83 ± 0.01, 0.94 ± 0.005, 1.11 ± 0.01, 1.18 ± 0.01 and 1.32 ± 0.04 eV, ensuring the presence of shallow and deep trap centers. The estimated initial electron density (∼10 6 cm −3 ) and charge carrier's lifetime (∼10 5 years at room temperature) indicate high sensitivity and minimal fading rate respectively. The material exhibits 14.16% temporal signal loss after 30 days. The calibration factor for the reusability of 1.93%, ensures the stability of material on repetitive irradiation. These findings confirm that the material possess structural stability against dose and suitable defects for reliable performance in high-range dosimetry applications.