Preparation And Properties Of Gd_xY_2-xO₃:Eu³⁺ Luminescent Materials

Oxide matrix phosphors are widely used in many fields such as bioluminescent probes,flat panel displays,high definition rear projection televisions,and X-ray scintillator materials and so on.The oxide material itself has the advantages of good optical properties,high mechanical strength,stable physicochemical properties,non-toxicity,easy preparation,and low preparation cost.The oxide material as a matrix has advantages of low phonon energy and high probability of transition.It can synthesize the desired phosphor with stable photoluminescent properties and become a research hotspot of rare earth photoluminescent matrix materials.How to improve the photoluminescence properties of oxide matrix phosphors has become the main research direction.This thesis mainly studies the effect of rare earth oxide composite matrix and non-rare earth metal ions on the photoluminescence properties of oxide matrix phosphors.In this work,the composite matrix GdxY(2-x)O3:Eu3+phosphor was prepared by hydrothermal method.The photoluminescence properties of GdxY(2-x)O3:Eu3+phosphors were improved by doping metal ions Mn+(K+,Li+,Al3+,Mg2*).The structural properties of the samples were analyzed by XRD.The surface morphology of the sample was observed by FE-SEM,and the photoluminescence intensity and quantum efficiency of the sample were analyzed by PL.The effects of composite matrix and metal ion doping on the photoluminescence intensity and quantum efficiency of the phosphor were studied.The main research contents and conclusions are as follows:(1)The photoluminescence intensity and quantum efficiency of Y2O3:Eu3+phosphors and Gd2O3:Eu3+phosphors prepared by hydrothermal method increased first and then decreased with the Eu3+concentration.When Y3+:Eu3+is 25:1,the photoluminescence intensity and quantum efficiency of the Y2O3:Eu3+phosphors reach maximum values.When Gd3+:Eu3+is 25:1,the photoluminescence intensity and quantum efficiency of the Gd2O3:Eu3+phosphors reach maximum values.Therefore,the optimum doping ratio of rare earth matrix ions and Eu3+is 25:1.That is,the optimum doping ratio of the rare earth matrix ions and Eu3+when preparing the GdxY(2-x)O3:Eu3+ phosphor is 25:1.(2)The GdxY(2-x)O3:Eu3+phosphor prepared by hydrothermal synthesis has good crystallinity and belongs to cubic system.The photoluminescence intensity and quantum efficiency of GdxY(2-x)O3:Eu3+ phosphors increase first and then decrease with the continuous incorporation of Gd3+.When x is 0.5,the photoluminescence intensity and quantum efficiency of Gd0.5Y1.5O3:Eu3+phosphor reach maximum values.Compared with the Y2O3:Eu3+ phosphor,the photoluminescence intensity is increased by 57.22%,and the quantum efficiency is increased by 90.20%.Compared with Gd2O3:Eu3+phosphors,the photoluminescence intensity increased by 21.29%and the quantum efficiency increased by 46.93%.(3)The crystal structure of Gd0.5Y1.5O3:Eu3+:Mn+ phosphor doped with metal ions Mn+(K+,Li+,Al3+,Mg2+)does not change.The doping of K+,Li+and Mg2+increases the intensity of the diffraction peak,and the incorporation of Al3+ greatly reduces the intensity of the diffraction peak.(4)The photoluminescence intensity of Gd0.5Y1.5O3:Eu3+:Mn+phosphors changed after doping metal ions Mn+(K+,Li+,Al3+,Mg2+).The photoluminescence intensity of the sample doped with 0.1 mM K+,0.1 mM Li+,0.05 mM Mg2+ was increased by about 136.48%,135.17%,92.55%,respectively.With the incorporation of Al3+,the photoluminescence intensity of Gd0.5Y1.5O3:Eu3+:Al3+ phosphors showed a decreasing trend.When the amount of Al3+incorporated was 0.2 mM,the photoluminescence intensity of the sample decreased by about 56.66%.(5)The quantum efficiency of Gd0.5Y1.5O3:Eu3+:Mn+phosphor doped with metal ions Mn+(K+,Li+,Al3+,Mg2+)is as follows.The quantum efficiency of the sample doped with 0.1 mM K+,0.1 mM Li+,0.05 mM Mg2+was increased by about 113.32%,111.46%,71.29%,respectively.With the incorporation of Al3+,the quantum efficiency of Gd0.5Y1.5O3:Eu3+:Al3+phosphors showed a decreasing trend.When the amount of Al3+was 0.2 mM,the quantum efficiency of the sample decreased by about 52.30%.In summary,the composite matrix oxide phosphor prepared by hydrothermal synthesis has good crystallization properties.Appropriate incorporation of non-rare earth metal ions can greatly improve the photoluminescence properties of the composite matrix oxide phosphor.