Eu2+ activated long persistent strontium aluminate nano scaled phosphor prepared by precipitation method

This paper reports the detailed preparation process of Eu2+ activated long lasting Sr4Al14O25 nano sized phosphor by precipitation method. Scanning electron microscopy (SEM), simultaneous DSC–TG, X-ray diffraction (XRD), photo luminescent spectroscope (PLS) and thermal luminescent (TL) spectroscope were employed to characterize the phosphor. SrAl2O4:Eu2+Dy3+ and Sr4Al14O25:Eu2+Dy3+ phosphors in nano scale were obtained by calcinating the precipitated precursor at 1200 and 1300 °C, respectively. Both the low-temperature product SrAl2O4:Eu2+Dy3+ and the high-temperature product Sr4Al14O25:Eu2+Dy3+ showed photoluminescence upon UV illumination with an emission peak at 480 and 505 nm, respectively. When compared to the powder obtained in conventional method, the nano sized powders revealed a blue shift in emission spectrum due to the decrease in grain size. Those two phosphors showed long persistent afterglow, and the Sr4Al14O25:Eu2+Dy3+ phosphor exhibited better afterglow property than SrAl2O4:Eu2+Dy3+ phosphor due to a deeper trap level and a higher trap concentration formed in the host material.