A transparent surface-crystallized Eu2+, Dy3+ co-doped strontium aluminate long-lasting phosphorescent glass-ceramic

A high-brightness Eu2+ and Dy3+ co-doped strontium aluminate-based transparent surface-crystallized long-lasting phosphorescent (LLP) glass-ceramic was synthesized using solid-state sintering method in CO atmosphere. The crystal structure, morphology and optical properties of the composite were characterized. By the X-ray diffraction diffusion (XRD) data, SrAl2O4 was demonstrated to be the crystallite in the glass-ceramic. The TEM photographs indicated that the sample had a universal small crystallite size about 10-20 nm on its surface. The SrAl2O4:Eu2+, Dy3+ crystallites were produced during the quenching process. After irradiated with ultraviolet (UV) light, the glass-ceramic emitted green long-lasting phosphorescence with an excitation peak at 375 nm and emission peak at 520 nm ascribed to the characteristic 5d-4f transition of Eu2+. Both the PL spectra and luminance decay revealed that this phosphor had efficient luminescence and long-lasting properties. By comparing with the heat-treated sample, the obtained transparent surface-crystallized LLP glass-ceramic puts up higher transparency and long phosphorescence, and could be obtained more easily.