Synthesis Of Sr₂Al₆O₁₁:Eu²⁺ With Solid State Reaction Method

Blue light-emitting materials with high optical output and high color rendering have important application in many fields, for instance, in semiconductor lighting and flat panel display, but the blue light emitting materials widely used today, such as BaMgAl10O17:Eu2+ , Sr5(PO4)3Cl:Eu2+ and Sr3Al10SiO20:Eu2+Ho3+, are not satisfactory. As a new kind of blue light-emitting material, Sr2Al6O11:Eu2+, with the emission peak of about 460nm and the quantum efficiency of about 90%, is a promising light-emitting material with high luminance and high color rendering.As a traditional method of preparing phosphor, high temperature solid state reaction is one of the methods used for the industrial production, so it is very important to extend the application of this method for synthesizing of Sr2Al6O11:Eu2+.Therefore, in this study, the blue light emitting Sr2Al6O11:Eu2+ were synthesized by using this method,the special low reaction temperatures were adopted so as to investigate the effects of synthesis temperature, B/Al ratio and holding time on the phase composition and the emitting properties of Sr2Al6O11:Eu2+, and the phase transformation in the synthesizing process was proposed, too.The results show: B2O3 plays a key role in the synthesis of Sr2Al6O11:Eu2+, the main phase of the sample is yellow-green (520nm) light-emitting SrAl2O4:Eu2+during the initial stage of reaction; the blue (460nm) light-emitting Sr2Al6O11:Eu2+ is a transitional phase which then gradually transforms into blue-green (490nm) light-emitting of Sr4Al14O25:Eu2+ when favorable external causes are possible. So that, samples with Sr2Al6O11:Eu2+ as the main phase can be obtained when the synthesis temperature, B/Al ratio and holding time are all selected properly, and this may be useful for the product of Sr2Al6O11:Eu2+.