Persistence luminescence and thermoluminescence of 260 nm UVC irradiated mixed-phase (BaAl2O4 - BaAl12O19) barium aluminate

Persistence luminescence (PerL) and thermoluminescence (TL) of BaAl₂O₄ - BaAl₁₂O₁₉ mixedphase compound under 260 nm UVC irradiation are studied. The sample shows PerL for more than 1 h post irradiation. TL glow curves of the sample recorded at 1 ^oC/s following irradiation to UVC radiation shows a composite glow peak between 30 and 230 °C. The TL intensity is found to be affected by thermal quenching. The activation energy for thermal quenching is estimated to be W = 0.85 ± 0.12 eV. A T_m-T_stop analysis reveals that the TL glow peak is composed of multiple first order components. The activation energy associated with the electron traps are found to vary from 0.66 to 1.70 eV. The density of the traps is high between 0.60 and 1.20 eV. Due to presence of continuous distribution of electron traps, there is an excellent scope of developing colour tuneable persistence luminescence phosphor using mixed phase barium aluminate.