Study On Solid-State Reaction Synthesis Strontium Aluminate Phosphors

After the short time irradiation of ultraviolet or visible light, Eu²⁺,Dy³⁺ co-activated strontium aluminate phosphors can provides strong andlong-time light in the dark, which is a new long persistent phosphor ofenergy-saving, highly efficiency, stability and non-pollution. Due to itsexcellent luminescent proprieties, it is used broadly and researched well.Recently, the temperature of synthesizing SrAl₂O₄:Eu, Dy phosphorsis higher, above 1350℃. To lower synthesis temperature, the crucialfactors influencing synthesis temperature are studied, such as the way ofadding alumiante, boron content and Al/Sr ratio, the results suggest thesynthesis temperature can be lowered by using Al(OH)₃ to replace Al₂O₃,increasing boron content or reducing Al/Sr ratio in certain field, while theluminescent proprieties can not be influenced and the excellentluminescent materials can be synthesized in 1050-1350℃.The influence on host phase composition and luminescentproprieties brought by the change of Al/Sr ratio is studied. It shows theincrease of Al/Sr ratio from 1.6 to 3.7 can make the phase compositionchange in the order: SrAl₂O₄→SrAl₄O₂₅→SrAl₁₂O₁₉。The luminescentspectra is determined by phase composition of host, if the Al/Sr ratio iswithin the scale 1.6-2.0, the product is SrAl₂O₄:Eu, Dy phosphor withgreen light. If within the scale 2.4-3.7, the product is SrAl₄O₂₅:Eu,Dyphosphor with glaucous light. If it is 2.2, the product emits blue light, thephase of which may be 2SrO·3Al₂O₃ by analysis.The samples of different rare earth ions content are prepared, theinfluence of concentration of Eu²⁺, Dy³⁺ ions on luminescent proprietiesis studied respectively. It shows the increase of concentration of Eu²⁺, Dy³⁺ ions can prolong the decay time of the samples, when theconcentration of Eu²⁺, Dy³⁺ ions respectively reach 3mol%, the sampleshave best luminescent properties, if earth ions content is further increased,it will be quenched.