The green long-after-glow luminescence from Tb3+-doped Sr2SiO4phosphors, 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 longafter-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 GdxBi0.95-xVO4:0.05Eu3+(x = 0–0.95) 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-xVO4:0.05Dy3+(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 YxBi0.95-xVO4:0.05Dy3+, 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 Y3+ content. An intense tunable characteristic emission of Dy3+ is observed with the increasing ratio of Y/Bi. Finally, the mechanism of luminescence of Dy3+ in the Y3xBi0.95-xVO4:0.05Dy+(x = 0–0.95) solid solution is analyzed and discussed.