Synthesis And Luminous Characteristics Of Eu Single Doped And Ce³⁺?Tb³⁺ Co-doped Scapolite Phosphors

Natural scapolites have stable physical and chemical properties,strong water resistance,and some of the scapolites contain S2-luminescent centers in nature.It can produce intense fluorescence,wide range of excitation and emission bands and easy to tune the fluorescence under near-ultraviolet light excitation.Therefore,we can make this series of phosphors is expected to become a new type of LED phosphor through the study of the natural scapolites of silicate structure.In the paper,based on the natural high luminous efficiency scapolite,we adulterate rare earth ions in the scapolite as matrix matrial and synthesize the tricolor phosphor by the traditional high temperature solid-state reaction and then investigate their luminescent properties,color coordinate and transfer mechanism between rare earth ions,and so on.The main results obtained are as follows:1.Natural scapolite is a kind of framework silicate mineral in silicate minerals and a kind of natural luminous ore with high luminous efficiency.Based on the formation conditions and chemical composition of natural high efficiency luminescent scapolite,a series of Na₄Ca₄Al₆Si₉O₂₄: xwt%Eu3+?x=0.5,1,2,5,6,8?phosphors were synthesized under a air atmosphere by traditional solid state reaction.It is found that the phosphor is a kind of high quality in the near ultraviolet?lex =393 nm?excitation by studying the crystal structure and fluorescence spectrum of the sample Three primary colors phosphor.It has the strongest emission peak at 613 nm and belongs to the5D0?7F2 electric dipole transition of Eu3+ ions,which can be applied to the red light of the trichromatic phosphor,which has potential research value and application prospect.It is a potential red luminescent material compared with the international standard value of red light?0.670,0.330?.2.A series of Na₄Ca₄Al₆Si₉O₂₄: ywt%Ce³⁺,3wt%Tb³⁺?x=1,2,4,5?phosphors were synthesized under a weak reducing atmosphere by traditional solid state reaction at1100 ? and their crystal structure were discussed.We investigated the luminescent properties of the doped Ce³⁺,Tb³⁺ and co-doped Ce³⁺,Tb³⁺ samples show that the codoped sample had a stronger luminescence intensity at 545 nm than that of a single Tb³⁺sample,due to the5D4?7F5 transition of Tb³⁺.The luminescent properties of Ce³⁺ samples with different concentrations were studied,their fluorescence lifetime and energy transfer mechanism were analyzed.The results show that the Tb³⁺ ions doped emission intensity and lifetime of5D4 ? 7F5 transition?545 nm?are also changed with the change of Ce³⁺ doping concentration,and the energy transfer ofCe³⁺ to Tb³⁺ was found.And the energy transfer efficiency is the highest when the mass ratio of Ce³⁺ and Tb³⁺ is 0.02:0.03.Through the measurement of color coordinates,it was found that with the change of Ce³⁺concentration,the luminescence of the sample could be adjusted in the green region,and the phosphor could be a new type of white LED phosphor.