Photoluminescence and thermoluminescence characteristics of BaCa(SO4)2: Ce mixed alkaline earth sulfate

A sensitive mixed alkaline earth sulfate phosphor BaCa(SO4)2:Ce has been studied for its photoluminescence (PL) and thermoluminescence (TL) characteristics. The phosphor was prepared by a co-precipitation method. Photoluminescence studies of this phosphor show the Ce3+ emission in the host at 327 nm for an excitation of 296 nm due to the 5d→4f transition. The intensity of the 327 nm band increases with increasing Ce concentration. The TL glow curve of the BaCa(SO4)2:Ce material shows a single peak at 223 °C, indicating single type of trapping site. The relative intensities of the peaks are found to increase with γ-ray exposure. The TL sensitivity of the phosphor is nearly 5–25 times higher than that of commercially available standard CaSO4:Dy phosphor. The trapping parameters of BaCa(SO4)2:Ce phosphor such as order of kinetics (b) (obeys the first order kinetics), activation energy (E) and frequency factor (S) were calculated by using Chenʹs half width method. The activation energy E (eV) and frequency factor S (s−1) were found to be 0.78 eV and 3.493×109 s−1 respectively.