Acta Optica Sinica, Volume. 34, Issue 4, 416004(2014)
Luminescent Properties and Crystal-Field Analysis for Novel Yellow-Green Phosphor CaWO4:Pr3+
Pr3+-doped cadmium tungstate yellow-green phosphors Ca1-xWO4xPr3+ (mole fraction x=0.1%, 0.3%, 0.5%, 0.7%) are successfully synthesized by the co-precipitation method. The crystal structure, morphology and photoluminescence (PL) properties are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and fluorescence spectrometer. The results show that CaWO4:Pr3+ has a tetragonal sheelite structure with space group I41/a. The SEM image shows that the grains are irregular with sizes ranging from 5 to 20 μm. The emission spectrum of the CaWO4:Pr3+ phosphor is characterized, its peaks locate at 530, 547,555, 602, 618, 637 and 648nm corresponding to the 3P1→3H5, 3P0→3H5, 3P0→3H5, 1D2→3H4, 3P0→3H6, 3P0→3H6 and 3P0→3F2 transitions of Pr3+, respectively. The strongest one appears at 648 nm when is excited by 487 nm which matches well with blue chips. The optimized concentration of Pr3+ is 0.5% for the highest PL emission intensity. In addition, to understand the fluorescent spectra of as-synthesized phosphors, a complete 91×91 energy matrix is built by an effective operator Hamiltonian including free ion and crystal field interactions. The fluorescent spectra for Pr3+ ion at the tetragonal (S4) Ca2+ site of CaWO4 crystal are calculated from a full diagonalization (of energy matrix) method. The fitting values are in good agreement with the experimental data.
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Feng Wenlin, Liu Qingsong, Zhang Weijie, Lü Likang, Cui Yue. Luminescent Properties and Crystal-Field Analysis for Novel Yellow-Green Phosphor CaWO4:Pr3+[J]. Acta Optica Sinica, 2014, 34(4): 416004
Category: Materials
Received: Oct. 21, 2013
Accepted: --
Published Online: Mar. 25, 2014
The Author Email: Wenlin Feng (wenlinfeng@126.com)