CHEN Wen, ZHENG Zishan
(School of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000, Fujian, China)
Abstract: Bluishlong persistent phosphor (LPP) Zn1-δAl2O4-δwas fabricated using a solid-state method in a reducing atmosphere. Zn vacancies, the luminescence centers in phosphors, were produced by decreasing a proper amount of Zn. Structural properties of the as-synthesized samples were characterized by X-ray powder diffractometer (XRD). The particle size of the phosphors was 45 nm, which was calculated by the Debye-Scherrer formula. There was one main emission peak of the phosphors at 467 nm affirmed by photoluminescence (PL). The thermoluminescence (TL) showed that there were two defects in the material with proper trap depths, 0.767 eV and 0.836 eV, respectively. Both Zn-deficient ratio and reducing atmosphere could significantly increase the material-defect concentration and improve the luminescence properties of the materials. The LPP materials were observed to have glowed to 4 hrs in darkroom. The photoluminescence mechanism of the Zn1-δAl2O4-δ materials was also discussed.
Key words: long persistent phosphors; ZnAl2O4; vacancy defects