The green long-after-glow luminescence from Tb3＋-doped Sr2SiO4 phosphors, which are synthesized by the high temperature solid state reaction in a reductive atmosphere, is observed in this paper. The results show that under ultraviolet excitation, the obtained phosphors produce an intense green-lighting-emission from the Tb3＋, and the green-lighting long- after-glow luminescence related to Tb3＋ can last half an hour after the irradiation source has been removed. Moreover, the effects of co-doping Li＋, Dy3＋, Er3＋, Gd3＋, and Yb3＋ with Tb3＋ on the decay properties and thermoluminescence properties are investigated to confirm the long-after-glow mechanism.
A complete solid solutions with monophasic zircon-type structure of vanadates of formula GdxBio.95-xVO4：0.05Eu3＋ （x = 04）.95） are synthesized by combined method of co-precipitation and hydrothermal synthesis. Their microstructures and morphologies are characterized by X-ray powder diffraction and transmission electronic microscope, and the results show that each of all the samples has a monophasic zircon-type structure. The absorption spectrum of the prepared phosphor shows a blue-shift of the fundamental absorption band edge with increasing the gadolinium content. Under UV-light and visible-light excitation, all the prepared phosphors show the typical luminescence properties of Eu3＋ in the zircon-type structure. The emission intensity of GdxBi0.95-xVO4：0.05Eu3＋ （x = 0.55） is strongest in all samples under UV-light and visible-light excitations. Finally, the mechanisms of luminescence of Eu3＋ in the GdxBi0.95-xVO4：0.05Eu3＋ （x = 0-0.95） solid solutions are analyzed and discussed.
We synthesize continuous solid solutions with monophasic zircon-type structure of vanadates of formula YxBi0.95 VO4：0.05Dy^3＋ （x = 0-0.95） using a combined method of co-precipitation and hydrothermal synthesis. The X-ray diffractometer patterns confirm the formation of a solid solution of YBi0.95-xVO4：0.05Dy^3＋, and the results show that all the samples have monophasic zircon-type structure. The absorption spectra of the prepared phosphors show a blue-shift of the fundamental absorption band edge with increasing Y^3＋ content. An intense tunable characteristic emission of Dy^3＋ is observed with the increasing ratio of Y/Bi. Finally, the mechanism of luminescence of Dya＋ in the YBi0.95 VO4：0.05Dya＋ （x = 0-0.95） solid solution is analyzed and discussed.
