CaAl2O4:Eu2+,Nd3+,Sr2+: A White-Light Phosphor with Yellow-Green Long Afterglow

A CaAl2O4:Eu2+,Nd3+,Sr2+ phosphor, with white light under irradiation and a yellow-green long afterglow, was prepared by the solid-state method. The emission spectra, afterglow spectra, and afterglow decay curve of the samples have been measured. It is found that the emission spectra under the irradiation of 400 nm are comprised of the blue-light emission (442 nm) and the yellow-green-light emission (538 nm), and the chromaticity coordinates were calculated to be x=0.289, y=0.341. After the irradiation source was removed, the blue emission decreased rapidly so that the white-light photoluminescence changed to the yellow-green afterglow and its persistent time was measured to be over 4 h.