The Preparation And Luminescent Properties Of Silicone Phosphate Phosphors

In this paper, the preparative process and luminescent properties of Sr₅（PO₄）₂SiO₄: Eu²⁺ phosphors were investigated. The microstructure and optical properties of all the phosphors were characterized by X-ray diffraction（XRD）, photoluminescence（PL） and International Commission on Illumination（CIE）. The primary work and conclusion are as follows:The first, the preparative process of Sr₅（PO₄）₂SiO₄: Eu²⁺ phosphors were explored in details. The effects of pre-sintering frequency, pre-sintering temperature, sintering temperature and sintering time on luminescence properties have been studied in detail, The best preparative parameters have been received. The stoichiometric chemicals were thoroughly mixed, then heated at 350℃（in air）, 850℃（in air） and 1400℃（in reductive atmosphere: N2: H2=10: 1） for 500 min, respectively. Samples must be grinded after each sintering for complete reaction.The second, the influence on luminescence properties which results from the doping concentration and test temperature was investigated in details. With the increase of Eu²⁺ doping concentration, the luminescence intensity increases. The maximum intensity is reached at x=0.015, and then decreases. The energy transfer from Eu1 to Eu2 and the red shift were also observed in the emission spectra according to the increasing of doping concentration. In addition, the emission wavelength shows a blue-shift with increasing temperature, but the blue-shift behavior cannot be described by the Varshini equation, it may be due to the stability of lattice structure and the phonon-assisted tunneling.The third, the each effect of BaF₂, Na₂CO₃, H₃BO₃ and NH4F fluxes on luminescence properties was researched. When doping BaF₂, Na₂CO₃ and H₃BO₃,fluxes respectively, each intensity of Sr₅（PO₄）₂SiO₄: Eu²⁺ first increases with increasing the doping amount until a maximum intensity is reached, and then decreases. But the intensity of Sr₅（PO₄）₂SiO₄: Eu²⁺ increases with increasing the NH₄F doping amount until a maximum intensity is reached, and then remains stable. This phenomenon is concerned with the performance of flux itself.The exploration about the preparative process and luminescent properties of Sr₅（PO₄）₂SiO₄: Eu²⁺ phosphors lays a foundation for a further research of this phosphor and plays a role in the theories of luminescence mechanism, energy transfer between different luminescence center, crystal field strength and the phonon-assisted tunneling.