Study On Preparation And Luminescence Of Red Vanadate Phosphor

With the technical development of FED and PDP, the requirement on the crystal size distribution, stability, luminescence efficiency, brightness and conductivity of the powder has been increasing. Among the large number of luminescent materials, rare-earth vanadate host luminescent materials are well known for their good chemical and thermal stability. In this paper, Four kinds of red phosphor systems based on YVO₄,Y(V, P)O4,KxMxYVO₄ and M3Y2(VO4)3 activated by Eu³⁺ were prepared through sol-gel method. X-ray diffraction, scanning electron microscopy and surface energy spectrum were used to study the phase structure, the morphology, element analysis and the luminescent properties of the phosphor. The paper aims at finding new types of luminescent materials with high-performance and low-cost.Frist, YVO₄:Eu red phosphor was synthesized by sol-gel method. The influence of sintering temperature on crystalline phase, morphology and luminescence were studied. Through analysis, the best sintering temperature was determined to be 1100℃. By studying the impaction of the concentration of activator on the fluorescence emission intensity, it is concluded that the best doping concentration of Eu³⁺ was determined to be 12%. Besides, by doping Bi3+ at a certain concentration of Eu³⁺, Eu³⁺ was found to be sensitized by Bi3+. Second, Y(V, P)O4:Eu red phosphor was synthesized. The fluorescent properties after doping PO43+ were studied. The results of the fluorescence intensity indicate that fluorescence intensity is the highest when V: P is 6:4. A series of KxMxYVO₄:Eu³⁺ (M=Mg, Ca, Sr) phosphor was synthesized, which is more economically effective. The phase structure of YVO₄ does not change when the amount of K and Mg replacing Y reached 25%. This series of phosphor synthesized by sol-gel process has uniform size, among which fluorescence intensity of K_0.25Mg_0.25Y_0.70VO₄:0.05Eu³⁺ is the highest. Finally, the influence of different doping concentration of alkaline earth metal in M₃Y₂(VO4)3:Eu(M=Mg, Ca, Sr) on fluorescence intensity was studied. As a result, the fluorescence intensity increased with the doping quantity before doping amount of M reached 20% and the fluorescence intensity of Mg₃Y₂(VO₄)₃:Eu is the best.