Synthesis of Sr4Al14O25:Eu2+,Dy3+ phosphor nanometer powders by combustion processes and its optical properties

Eu2+,Dy3+ co-doped strontium aluminate (Sr4Al14O25) phosphor with high brightness and persistent luminescence were prepared via a combustion process using SrAl2O4 as precursors, followed by heating the precursors at 1300 °C in a protective atmosphere of N2. The precursors and target powders were further investigated by X-ray diffractometer (XRD), photoluminescence excitation and emission spectra (PL), transmission electron microscopy (TEM) and brightness meter. The result showed that the single-phase Sr4Al14O25 was formed at 1300 °C. The phosphor powders have two main peaks near 403 and 482 nm, respectively, which are ascribed to two types of Eu2+ that existed in the Sr4Al14O25 matrix crystal. The average particle size of the Sr4Al14O25:Eu2+,Dy3+ phosphor nanoparticles ranges from 20 to 40 nm. The decay time of the persistence indicated that the nanometer phosphor have bright phosphorescence and maintain a long duration.