A novel white-emitting phosphor ZnWO_4:Dy^(3+)

A new white luminescent material Dy3＋ doped ZnWO4 was synthesized by hydrothermal route followed by calcining proc- ess. The phase structure, morphology and luminescent properties of as-synthesized samples were characterized by X-ray diffraction, scanning electron microscopy and fluorescence spectrophotometry, respectively. The results indicated that the sample was pure ZnWO4：Dy3＋ only when the pH value of the reaction system was 6. The ZnWOa：Dy3＋ sample was composed of spherical particles, and the particle size was about 80-130 nm. The excitation spectrum consisted of a broad band ascribed to the charge transfer transi- tion from oxygen ligand to tungsten ion. The emission spectrum of ZnWO4：Dy3＋ was composed of two major parts： the broad band attributing to the intrinsic emission of WO42- and the 4F9/2→6H15/2 transition of Dy3＋, and the sharp emission peak corresponding to the 4F9/2→61-113/2 transition of Dy3＋. The optimal emission intensity of the Zn1-xWOa：Dy3＋x phosphors was realized when x= 1.5 mol. %. Moreover, all of the ZnI_xWOa：Dy3＋ （x=0.5 mol.%, 1 mol.%, 1.5 mol.%, 2 mol.%） phosphors could exhibit white light emission, which could be potentially applied in white lighting-emitting diodes.