Preparation And Properties Of Europium Doped Titanate Phosphors

White light emitting diode（white LED）,as a new generation of solid lighting devices,has the advantages of safety,environmental protection and no pollution,high efficiency,small size,long life,low power consumption and so on.It can be applied to many fields.Titanate matrix phosphors have good physical and chemical properties,low synthesis temperature and easy doping,so they have a good application prospect.In this paper,Eu³⁺doped red titanate luminescent materials were prepared by using Eu³⁺as activator.The structure and luminescent properties of Eu³⁺doped red titanate luminescent materials were studied by means of DTA-TGA,XRD and PL.（1）Eu³⁺doped BaTiO₃ fluorescent materials were prepared by sol-gel method.The results show that tetragonal BaTiO₃:Eu³⁺can be obtained when the calcination temperature is650-800℃,and 700℃is the best calcination temperature.The optimal doping concentration of Eu³⁺is 9%（mo1）.The quenching mechanism is electric quadrupole-electric quadrupole interaction.Fluorescence test results show that the series of phosphors can be excited in the near ultraviolet 394nm and blue 464nm,the main emission peak is located at 618nm,Eu³⁺⁵D₀→⁷F₂electric dipole transition,BaTiO₃:Eu³⁺phosphors emit red light.Compared with BaTiO₃:Eu³⁺phosphors,the doping of Sr²⁺ions changes the crystal structure and luminescence properties of BaTiO₃.When Ba:Sr=0.6:0.4,the color coordinate of the phosphor is（0.6529,0.3468）,which is close to the standard red color coordinate NTSC（0.67,0.33）.It is an excellent red phosphor. optimal doping amount of Tb³⁺is 9%（mo1）,and the quenching mechanism is electric dipole-electric dipole interaction.（2）Using ethylene glycol as stabilizer,Eu³⁺doped NaLaTi₂O₆red phosphor was prepared by sol-gel method.The results show that the optimal calcination temperature of NaLaTi₂O₆:Eu³⁺is 900℃,and the ultraviolet light at 394nm is used as the optimal excitation wavelength to obtain the red luminescent materials dominated by the ⁵D₀→⁷F₂galvanic transition of Eu³⁺.NaLaTi₂O₆:Eu³⁺,Tb³⁺doping in Tb³⁺phosphors enhanced the luminescence intensity of NaLaTi₂O₆:Eu³⁺.When the concentration of Eu³⁺is 3%（mo1）,the optimal doping amount of Tb³⁺is 9%（mo1）,and the quenching mechanism is electric dipole-electric dipole interaction.（3）BaTiNb₉O₄₂:Eu³⁺ phosphors were prepared by using boric acid as a co-solvent and high temperature solid phase method.The results show that the best calcination temperature is 1200℃.The phosphor can be excited by near-ultraviolet light at 394nm,and the main emission peak is orange-red light at 598nm.The lifetime of phosphors decreases with the increase of Eu³⁺concentration,and the luminescence intensity reaches the maximum when the doping concentration of Eu³⁺is 9%（mo1）.Tb³⁺doped BaTiNb₉O₄₂:Eu³⁺phosphors can improve the luminescence properties of the phosphors by transferring the energy from Tb³⁺ions to Eu³⁺through the electroquadrupole interaction with Tb³⁺.When the optimal doping concentration of Tb³⁺is 11%（mo1）,the luminescence performance of the sample is the best.