Fig illustrates the decay curves of the green afterglows

3, the CIE chromaticity coordinates of the PL are calculated to be (0.215, 0.288) for the SrAl2O4:Dy3+ phosphors synthesized at 600 °C. In contrast to our bluish green PL from the SrAl2O4:Dy3+ phosphors, Omkaram and Buddhudu reported white PL from Dy3+ doped MgAl2O4 [11], and they attributed the color superimposition of the narrow blue emission at 480 nm and the narrow yellow emission at 575 nm to be responsible for their white colored emissions.