Study On The Preparation Structure And Luminescent Properties Of The Rare Earth Doped BaSr₂Gd(PO₄)₃ Phosphor

In recent decades,energy-saving and environmentally friendly luminescent materials have been the focus of people's research,in which phosphate-based phosphors have achieved remarkable results in some fields,such as:display,luminescence.At the same time,phosphate-based phosphors have been widely used.The advantages of this kind of phosphors are as follows:good luminescence performance and simple synthesis process.LED has high luminous efficiency,long service life,and the LED energy-saving effect is also very good.Therefore,it has the reputation of the fourth generation lighting source.In this paper,a new phosphate-luminescent material was prepared by adding Sm³⁺,Dy³⁺,Eu³⁺and Tm³⁺into BaSr₂Gd(PO₄)₃matrix by means of high temperature solid phase method,and the luminescence characteristics were studied in detail.There is the energy transfer between ions,such as Dy³⁺to Tm³⁺,Sm³⁺to Eu³⁺,Dy³⁺to Eu³⁺,and under different doping concentrations and different rare earth ions the color coordinate value is calculated to determine the starting light color.Through the analysis of experimental data,it is concluded that BaSr₂Gd(PO₄)₃:Sm³⁺/Dy³⁺/Eu³⁺/Tm³⁺has great potential to become a new type of single matrix LED phosphor under the excitation of ultraviolet light.First,BaSr₂Gd_(1-x)(PO₄)₃:x Dy³⁺(x=0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.180.20)luminescent material was prepared by high temperature solid phase method.The emission spectrum and excitation spectrum of the material were measured,and the optimal concentration of Dy³⁺doping was x=0.08 under the excitation of 350nm.The quenching mechanism of Dy³⁺was analyzed in the matrix BaSr₂Gd(PO₄)₃,and it was due to the action of the electric dipole and the electric dipole between the rare earth ions in the doped Dy³⁺.Secondly,BaSr₂Gd_(1-x-z)(PO₄)₃:x Dy³⁺,z Tm³⁺and BaSr₂Gd_(1-x-y)(PO₄)₃:x Dy³⁺,y Eu³⁺were prepared by high temperature solid phase method,and their emission and excitation spectra were analyzed.The energy transfer from Dy³⁺ion to Tm³⁺ion and Dy³⁺to Eu³⁺was proved.Finally,the color coordinate values of two kinds of phosphors were calculated,and their luminescence colors were from blue-green to blue-blue and yellow-green to red-orange respectively.Sm³⁺,Eu³⁺single and double admixture were added to matrix BaSr₂Gd(PO₄)_3,and single matrix BaSr₂Gd_(1-x-y)(PO₄)₃:x Sm³⁺-y Eu³⁺phosphor was prepared.The attenuation life of Sm³⁺in double-doped phosphors was calculated by spectral analysis,and the energy transfer between Sm³⁺and Eu³⁺was obtained.Finally,BaSr₂Gd_(1-x-y-z)(PO₄)₃:x Dy³⁺,y Eu³⁺,z Tm³⁺phosphors were prepared under uv excitation at 388nm.The color coordinates of 0.04Dy³⁺,0.03Eu³⁺,0.02Tm³⁺phosphors are(0.329,0.349).The results indicate that the sample studied may become a single matrix WLEDs phosphors for future lighting applications.