Preparation And Luminescence Properties Of Ba_3-x-yMg_0.9Si₂O₈:Eu_x²⁺,Tb_y³⁺,Mn_0.1²⁺Red-Emitting Phosphors

According to the requirements of the near ultraviolet/purple chip to red phosphors, we synthesized that Ba3-x-yMgo.9Si2O8:Eux2+,Tby3+,Mno.12+red phosphors using high temperature solid phase synthesis method, investigated the structure, morphology as photoluminescent properties of the phosphors by means of X-ray diffraction, photoluminescence, photoluminescence excitation, scanning electron microscopy, fluorescence microscope, energy dispersive X-ray spectroscopy, and cathode ray luminescence, and discussed the role of Tb3+in the formation of Ba3MgSi2O8phase and the energy transfer between Eu2+and Mn2+. The experimental works and results are briefly introduced as follows.First of all, we synthesized the Ba3MgSi2O8:Eu2+, Mn2+phosphor by calcining reactants at1300℃for2hours. Photoluminescence test shows that Ba3MgSi2O8:Eu2+,Mn2+have three emission bands around437nm,505nm, and620nm, respectively under the excitation of a nearly ultraviolet light chip. The experimental data of scanning electron microscopy, Energy dispersive X-ray spectroscopy and cathode ray luminescence show that the437nm and620nm emissions come from the Ba3MgSi2Os:Eu2+, Mn2+, while the505nm band comes from an impurity phase, probably Ba2SiO4:Eu2+. Further, we synthesized a new Ba3MgSi2O8: Eu2+,Mn2+,Tb3+red phosphor by the high temperature solid state reaction method. Experimental results show that Tb3+doping can suppress the formation of Ba2SiO4:Eu2+impurity, and significantly weaken the green emission at505nm. Photoluminescence spectra show Tb3+doping can greatly increase the emission intensity of620nm band of the phosphor. The620nm red emission reach maximum relative to the437nm blue emission, when the concentration of Tb3+up to0.1, at this composition the emission color coordinate of the phosphor is located at (0.52,0.31). Photoluminescence excitation spectra show that Eu2+, Tb3+and Mn2+can form effective energy transmission channel among them, the existence of Tb3+can enhance energy transfer between Eu2+and Mn2+. Temperature dependent photoluminescence measurements shows that the Ba3MgSi2Os:Eu2+,Mn2+,Tb3+red phosphor can maintain more than80%room temperature photoluminescence intensity at150℃, and therefore is a promising red-emitting phosphor for white LED.