Research On Preparation And Luminescence Properties Of Rare Earth-Doped Oxy-acid Salt LED Phosphors

The role of LEDs in indoor lighting systems and displays is becoming more and more important,and phosphors are an important part of LEDs.It is one of the current research hotspots to find the synthesis conditions of rare earth ion phosphovanadate phosphors and explore the quality and luminescence properties of rare earth ion phosphovanadate phosphors.In this paper,RE:YP_0.9V_0.1O₄(RE:Eu³⁺,Dy³⁺,Tb³⁺and Tm³⁺)phosphors,Dy³⁺-Eu³⁺double doped,Tb³⁺-Eu³⁺double doped,Tm³⁺-Eu³⁺double doped,Dy³⁺-Eu³⁺-Tb³⁺co-doped and Tb³⁺-Eu³⁺-Tm³⁺co-doped YP_0.9V_0.1O₄ phosphors were prepared by hydrothermal method The detailed experimental contents and results are as follows:（1）Eu³⁺mono-doped YP_0.9V_0.1O₄ phosphors under different experimental conditions were prepared by hydrothermal method.and the red luminescence performance was better when the P/V molar ratio was 9:1,the Eu³⁺doping concentration was 7%,the p H value was1,the reaction time was 54 hours,the reaction temperature was 200°C,and the sodium citrate/total metal cation was 0:1;（2）Dy³⁺,Tb³⁺and Tm³⁺single-doped YP_0.9V_0.1O₄ phosphors were prepared.The excitation wavelength of Dy³⁺,Tb³⁺and Tm³⁺mono-doped YP_0.9V_0.1O₄ phosphors were all determined to be 278 nm.Under this excitation wavelength,the doping concentrations of Dy³⁺,Tb³⁺and Tm³⁺single-doped YP_0.9V_0.1O₄ phosphors is 2%,5%and 1%,respectively.The CIE color coordinates of all phosphors were within the blue region;（3）Dy³⁺-Eu³⁺double doped and Dy³⁺-Eu³⁺-Tb³⁺triple doped YP_0.9V_0.1O₄ phosphors were prepared.There is an energy transfer process from Dy³⁺to Eu³⁺in Dy³⁺-Eu³⁺double doped YP_0.9V_0.1O₄ phosphor;Dy³⁺-Eu³⁺-Tb³⁺tri-doped YP_0.9V_0.1O₄ phosphor has an energy transfer process from Dy³⁺and Eu³⁺to Tb³⁺.Dy³⁺-Eu³⁺double doped YP_0.9V_0.1O₄ phosphor realizes the light color change from blue light to cold white light;Dy³⁺-Eu³⁺-Tb³⁺tri-doped YP_0.9V_0.1O₄ phosphor realizes the light color change from white light to orange light.The CIE color coordinates of YP_0.9V_0.1O₄:2%Dy³⁺,4%Eu³⁺,1%Tb³⁺phosphor are（0.3613,0.2884）,the color temperature is 3730 K,and the thermal stability is good.It can be used as indoor lighting W-LED single-phase warm white phosphor;（4）Tb³⁺-Eu³⁺,Tm³⁺-Eu³⁺double doped and Tb³⁺-Eu³⁺-Tm³⁺triple doped YP_0.9V_0.1O₄phosphors were prepared.There is an energy transfer process from Tb³⁺to Eu³⁺in Tb³⁺-Eu³⁺double doped YP_0.9V_0.1O₄ phosphor;there is an energy transfer process from Tm³⁺to Eu³⁺in Tm³⁺-Eu³⁺double doped YP_0.9V_0.1O₄ phosphor;there is an energy transfer process from Tb³⁺and Eu³⁺to Tm³⁺in Tb³⁺-Eu³⁺-Tm³⁺tri-doped YP_0.9V_0.1O₄ phosphor.Tb³⁺-Eu³⁺double doped YP_0.9V_0.1O₄ phosphor realizes the light color change from cold white light to orange red light.Tm³⁺-Eu³⁺double doped YP_0.9V_0.1O₄ phosphor realizes the light color change from blue light to pink white light;Tb³⁺-Eu³⁺-Tm³⁺tri-doped YP_0.9V_0.1O₄phosphor realizes light color change color from blue to white.Among them,the CIE color coordinates of YP_0.9V_0.1O₄:5%Tb³⁺,1%Eu³⁺phosphors are（0.3190,0.2885）,which are quitely close to the standard white light,and the color temperature is 6380 K and good thermal stability.The results show that the phosphor is a candidate material for W-LED single-phase cold white phosphor.