Study On The Synthesis And Crystal Growth Of Rare Earth Vanadium Phosphate Phosphors

Rare earth phosphors are mainly used in two major areas:lighting and display.In recent years,with the technology upgrades in these two fields,the development of better performance phosphors become more and more important.Phosphate is a kind of matrix material with excellent properties because of its stable physical and chemical stability,low synthetic temperature and low cost.In addition to phosphate,rare earth vanadate phosphors have excellent luminescent properties and thermal stability under UV excitation.Introducing VO₄^3- into the phosphate matrix and replacing part of PO₄^3- can enhance the performance of the phosphor.In this paper,Eu³⁺ is selected as the active ion,the matrix is vanadium phosphate yttrium formed by VO₄^3- replacing part of PO₄^3- and a series of phosphors are synthesized by chemical co-precipitation method,the optimum ratio of P:V is 6:4.Based on this,the Eu³⁺ -doped rare earth phosphors with different concentrations were prepared and the matrix is Y(P_0.6 V_0.4 ) O₄.X-ray powder diffraction?XRD? ,scanning electron microscopy?SEM? ,Fourier transform infrared spectroscopy?FT-IR? ,and photoluminescence?PL? were used to study the crystal structure,morphology,and luminescence properties of rare earth phosphors.The results show that the fluorescence performance of Y_0.95 (P_0.6 V_0.4 ) O₄:0.05Eu³⁺ is best.When the doping concentration of Eu³⁺ is less than 5%,the luminescence intensity increases with the increase of Eu³⁺ doping concentration,and when the doping concentration is more than 5%,the concentration quenching occurs due to the reabsorption effect and the luminous intensity is weakened.In addition,the effect of heat treatment temperature on the luminescent properties of phosphors was studied,and the optimum heat treatment temperature was determined to be 1000?.Y_0.95 (P_xV_1-x ) O₄:0.05Yb crystals were grown by flux.Using Pb₂P₂O₇ as fluxing agent,Y_0.95 (P_0.7 V_0.3 ) O₄:0.05Yb and Y_0.95 (P_0.8 V_0.2 ) O₄:0.05Yb flake crystals were successfully grown by spontaneous nucleation.The factors affecting the crystal growth is discussed,including the properties of the flux,temperature control program,temperature field and impurities,and so on.