文摘
Pr3+exhibits prominent red emission in most oxide phosphors, which derives from the 1D2→3H4 transition, and green or blue emission from 3P0→3H4, 5 transitions are normally less intense in most cases. However, a greenish-blue emission was observed from Sr3TaAl3Si2O14:Pr3+prepared via solid state reaction. All as-prepared phosphors were studied systematically by X-ray diffraction (XRD), photoluminescence spectra, decay curves, long afterglow (LAG) spectra and thermoluminescence (TL) glow curves. Based on the excitation and emission spectra, the Sr3TaAl3Si2O14 (STAS) host is proved to be a self-activated luminescent host lattice. In the emission spectra for Pr3+doped STAS, the predominant greenish-blue emission locating at ~489 nm and ~507 nm coming from 3P0,1→3H4 transitions were observed. And the different mechanisms for concentration quenching in both cases were discussed. At last, a model was proposed on the basis of experimental results to discuss the LAG mechanism of STAS:Pr3+in detail.