Thermoluminescence properties of Eu-doped and Eu/Dy-codoped Sr₂ Al₂ SiO₇ phosphors

We report the thermoluminescence properties of Sr_1.96 Al₂ SiO₇ :Eu_0.04 and Sr_1.92 Al₂ SiO₇ :Eu_0.04 Dy_0.04 phosphors. These phosphors were prepared by a high-temperature solid-state reaction method. The prepared phosphors were characterized by X-ray diffraction. A 254 nm source was used for ultraviolet (UV) irradiation and a ⁶⁰ Co source was used for γ-irradiation. The effect of heating rate and UV-exposure were examined. The thermoluminescence temperature shifts to higher values with increasing heating rate and thermoluminescence intensity increases with increasing UV exposure time. The trapping parameters such as activation energy (E), order of kinetics and frequency factor (s) were calculated by peak shape method. The effect of γ- and UV-irradiation on thermoluminescence studies was also examined.