Luminescence of barium aluminate phosphors activated by Eu2+ and Dy3+

Abstract Long afterglow barium aluminate phosphors activated by Eu2+ and Dy3+ were successfully prepared with various Al/Ba ratios from 2 to 5 and sintering temperatures from 1050 to 1400 °C. XRD measurements revealed that the content of the BaAl12O19 crystalline phase increases with increasing Al/Ba ratios and sintering temperature. In accord with these results, the luminescence spectra showed a peak shift from 500 (due to BaAl2O4:Eu2+) to 440 nm (due to BaAl12O19:Eu2+) when the sintering temperature was increased from 1050 to 1400 °C. The spectral changes and afterglow characteristics were closely related to the relative contents of the BaAl2O4 and BaAl12O19 phases.