Design And Synthesis Of Double Perovskite Phosphors

Perovskite complex oxides have attracted much attention in electrical,magnetic and catalytic fields because of their simple synthesis process,good thermal and chemical stability.In recent years,the rare earth ions doped perovskite oxide M₂^IM^IIMO₆(M^I=Ca,Sr,Ba,Mg,Zn;M^II=Ca,Sr,Mg,Zn,Bi,Gd,La,Y;M=W,Mo,V,Ti,P,Nb,Ta)also have been widely studied as phosphor host materials.The perovskite complex oxides contain a large variety of crystals types and can allow a large number of ions to be replaced.In this paper,BiCa₂VO₆ and La₂MgTiO₆ host phosphors doped with Eu³⁺,Sm³⁺,Bi³⁺,Gd³⁺,Dy³⁺have been designed and synthesized by high temperature solid state method.1.Bi_1-xCa₂VO₆:xEu³⁺red phosphors were synthesized by high temperature solid state method.The phase structure and morphology of those products were characterized by XRD and SEM.The main excitation peak of Bi_1-xCa₂VO₆:Eu³⁺phosphors locate 395nm and can be effectively excited by ultraviolet light emitted by InGaN chips.The optimum doping concentration of Eu³⁺is 0.1 mol.The T₅₀ of Bi_0.9Ca₂VO₆:0.1Eu³⁺phosphor about is 150?.The thermal quenching activation energy?35?E is 0.31 eV,which indicates the phosphor has good thermal stability.2.A series of La_2-x-yMgTiO₆:xEu³⁺,yA³⁺(A³⁺=Sm³⁺,Bi³⁺,Gd³⁺)red phosphors were synthesized by high temperature solid state method.The phase structure and morphology of those products were characterized by XRD and SEM.The main excitation peaks of single doped Eu³⁺and co-doped Eu³⁺,Sm³⁺/Bi³⁺/Gd³⁺phosphors are all near 396 nm.It can be effectively excited by ultraviolet InGaN chip.The main emission peaks are 615 nm.The fluorescence intensity of La₂MgTiO₆ phosphors in single doped Eu³⁺was relatively weaker.The fluorescence properties of La₂MgTiO₆:Eu³⁺phosphors were greatly improved by co-doping sensitizer Sm³⁺/Bi³⁺/Gd³⁺.The fluorescence properties are 1.88 times,1.31 times and 1.32 times as much as that of single doped Eu³⁺respectively.3.A series of La_2-x-yMgTiO₆:xB³⁺,yEu³⁺(B³⁺=Sm³⁺,Bi³⁺,Dy³⁺)phosphors were synthesized by high temperature solid state method.The phase structure and morphology of those products were characterized by XRD and SEM.Firstly,a series of single doped La₂MgTiO₆:Sm³⁺/Bi³⁺/Dy³⁺phosphors are prepared.Secondly,the red component was added by co-doping Eu³⁺.By changing the concentration of doped ions to adjusting the ratio of red,green and blue trichromatic,the phosphors with difficent colors were obtained.Meanwhile,the energy transfer mechanism between Sm³⁺/Eu³⁺,Bi³⁺/Eu³⁺and Dy³⁺/Eu³⁺was studied.The energy transfer efficiency at the optimum doping concentration is 57.1%,19.2%and 53.9%,respectively.The energy transfer mechanism is q-q interaction,d-d interaction and d-d interaction,respectively.