Co-precipitation Synthesis And Study Of Long Afterglow Phosphors

Long afterglow luminescence materials, which have excellent luminescent properties have been widely investigated and application. It appears some new synthesized methods to effectively improve the luminescent property with the new luminescent materials of the rare earth come forth.hi this paper, the Y₂O₂S:R³⁺,Mg²⁺,Ti⁴⁺(R³⁺=Eu³⁺,Sm³⁺,Tb³⁺) phosphors were synthesized first by co-precipitation method. Its x-ray diffraction patterns, the structure of crystal lattice and the luminescent properties were studied. Compared with the Y₂O₂S:Eu³⁺,Mg²⁺,Ti⁴⁺ phosphorescence prepared by high temperature solid state method, we can see that the phosphors prepared by co-precipitation method not only have small granularity and loosen structure but also can made the Eu³⁺ enter into crystal lattice and form luminescent centre easily. So the luminescent properties of Y₂O₂S:Eu³⁺,Mg²⁺,Ti⁴⁺can improve effectively.The change of emission spectra in Y₂O₂S:Sm³⁺,Mg²⁺,Ti⁴⁺and Y₂O₂S:Tb³⁺,Mg²⁺,Ti⁴⁺ were studied though altering the concentration of activator. The emission spectra of Y₂O₂S:Sm³⁺,Mg²⁺,Ti⁴⁺ increased with the increasing of Sm³⁺. In the emission spectra of Y₂O₂S:Tb³⁺,Mg²⁺,Ti⁴⁺ phosphors, the spectra rooted in the ⁵D₄→⁷F_s increased straight and the spectra come from ⁵D₃→⁷F₅ increased firstly and decreased afterwards with the increased of Tb³⁺. The intensity was the strongest when the concentration of Tb³⁺ is 2.0%.The long afterglow phosphor (Ca_1-xSr_x)S:Eu²⁺ was fabricated by co-precipitation. The effect of the ratio of Ca²⁺ and Sr²⁺ on the crystal lattice and the effect of the concentration of Eu²⁺ on the luminescent properties through the analysis of XRD, excitation and emission. The blue shifts were observed when Sr²⁺ increased. The luminescent properties reach the best when the concentration of Eu²⁺ is 0.6% and the sintering temperature is 1100℃.Through these investigations in this paper, it made us have more realize and understand for the long afterglow materials by co-precipitation method and offer important experiment foundation for more study the formation method of this material.