title: Preparation, Energy Transfer Characteristics and Colorimetric Properties of Na₂Dy₄(WO₄)₇:Eu³⁺ Nanophosphors.
abstract: Eu³⁺-doped Na₂Dy₄(WO₄)₇ nanophosphors were synthesized via a co-precipitation method. The crystal structure and morphology of the nanophosphors were characterized by X-ray diffraction analysis and field emission scanning electron microscopy, respectively. For all Eu³⁺ doping concentrations, spherical particles with an average diameter of about 40 nm and consisting of a pure Na₂Dy₄(WO₄)₇ phase were obtained. The excitation and emission properties of the nanophosphors were examined by fluorescence spectroscopy and the energy transfer between Eu³⁺ and Dy³⁺ was studied. Furthermore, the influence of the Eu³⁺ concentration on the color coordinates and luminescence intensity is discussed. The nanophosphors could easily be excited by ultraviolet (UV) and near-UV light corresponding to the f-f transitions of Dy³⁺. The color coordinates of the nanophosphors light emission are in the white light region and the Commission Internationale de l'Éclairage (CIE) coordinates of the nanophosphors light emission varied between (0.331, 0.354) and (0.405, 0.368) depending on the Eu³⁺ doping concentration.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Chuanjun
authors.initials: C
authors.lastname: Yuan
authors.forename: Ruinian
authors.initials: R
authors.lastname: Hua
authors.forename: Tianqing
authors.initials: T
authors.lastname: Liu
authors.forename: Kedong
authors.initials: K
authors.lastname: Song
authors.forename: Jicheng
authors.initials: J
authors.lastname: Yu
authors.forename: Dongxin
authors.initials: D
authors.lastname: Tang
authors.forename: Ye
authors.initials: Y
authors.lastname: Gao
authors.forename: Baojiu
authors.initials: B
authors.lastname: Chen
mesh_terms: D003124:Colorimetry / Q000379:methods; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D045663:Quantum Dots / Q000737:chemistry*