Study On Preparation Of Phosphorescent Phosphor SrAl₂O₄: Eu～(2+), Dy～(3+)(M) By Combustion Method

In present work, The phosphorescent phosphor SrAl₂O₄: Eu²⁺, Dy³⁺(M) were prepared by combustion method. The research progress and facing difficulties of the phosphors are systematically summarized and reviewed in this paper. The synthesis, luminescent properties, fluorescence mechanism and afterglow characteristics of phosphors were investigated by the means of XRD, SEM, Fluorescent Spectra Analysis, Thermoluminescence Spectra and so on. Research on the phosphors is made to develop new high-efficient, long-persistent phosphors without radioactive substance.The effects of host composition , Eu²⁺ Dy³⁺content, different additives and preparation conditions on the properties of the phosphor were inspected; It was found that the ratio of Al to Sr strongly affects the emission wavelength, as observed by fluorescence spectra. Based on XRD analysis, the effect of the ratio of Al to Sr on the host structure was discussed and an explanation on the color change was proposed; It is discovered that the emission intensity of phosphors increased firstly and reached high at 0.4%mol then decreased with the content of Eu²⁺ ions because of the quenching concentration of the phosphors; Based on the research on the thermoluminescence spectra and fluorescent decay, Dy³⁺ plays an important role in the system resulted in different decaytime. With the content of Dy³⁺ increasing, the depth of trapping levels in the phosphors increases, yet the emission intensity tends to decrease, the best concentration of the Dy³⁺ is 0.4%mol; The influence of P2O5 ,H3 BO3 ,CaF2 Additives on the luminescent properties of SrAl₂O₄: Eu²⁺, Dy³⁺ was studied. The emission spectra show that the main emission peaks of SrAl₂O₄: Eu²⁺, Dy³⁺ doped with the additives intend to blue shift compared to that without additives .In addition, the luminescent properties of SrAl₂O₄: Eu²⁺, Dy³⁺ is improved by the additives P2O5 ,H3 BO3.The phosphors has been synthesized by combustion of mixtures of respective metal nitrates and urea. The process is energy-saving, instantaneous and safe. The reaction can be completed at 600-700℃furnace temperature in 3-5min , which is much lower than that used in traditional solid-state reaction process(1350-1500℃).