Effects Of Non-rare-earth Metal Ions Doping On The Fluorescent Properties Of Yttrium Oxide Powder

Y₂O₃:Eu³⁺ phosphor is the traditional commercial red phosphor and it is widely used in the field of energy saving lamp and cathode luminescence and so on. Y₂O₃:Eu³⁺ phosphor has those advantages of stable physicochemical properties, good thermal stability, high fluorescent properties, high purity of red light color and so on. High temperature solid state method is usually used in industrialized production of Y₂O₃:Eu³⁺ phosphor. High temperature solid state method has strict requirement for equipments, and the reaction temperature is high, energy consumption is high, production cost is high. Besides, the product purity is not high and the fluorescent efficiency is low.In this thesis, hydrothermal method of which reaction conditions are mild was used to prepare Y₂O₃:Eu³⁺ phosphor, and the best molar ratio of Y³⁺ and Eu³⁺ was studied. O n the basis of the best molar ratio of Y³⁺ and Eu³⁺, non-rare-earth metal ion M(M=Li+, K+, Mg2+, Al³⁺) were doped to improve phosphor’s properties. The luminescent intensity and the quantum efficiency of the phosphor were measured by PL. The c rystallization property of the phosphor was analyzed by XRD. The appearance characteristics of the phosphor were observed by FE-SEM. The effects of different non-rare-earth metal ions and different doping amount on the properties of phosphor were discussed from the aspects of luminescent intensity, quantum efficiency, crystallization property and surface morphology. The main research results were as follows:（1） When the molar ratio of Y³⁺ and Eu³⁺ was 25:1, both the luminescent intensity and the quantum efficiency of the phosphor were all reached the maximum. So the best molar ratio of Y³⁺ and Eu³⁺ was 25:1.（2） The moderate doping amount of non-rare-earth metal ions M(M=Li+, K+, Mg2+, Al³⁺) can improve the crystallization properties of the phosphor, but over doping Li+ would decrease the crystallization properties of the phosphor.（3） When Y³⁺:Eu³⁺:K+=25:1:1, both the luminescent intensity and the quantum efficiency of the Y₂O₃:Eu³⁺:K+ phosphor with Y³⁺:Eu³⁺:K+=25:1:1 were the maximum among the Y₂O₃:Eu³⁺:K+ phosphor. The luminescent intensity and the quantum efficiency were increased by 19.1% and 27.1% respectively compared with the Y₂O₃:Eu³⁺ phosphor. The best doping ratio of K+ is Y³⁺:Eu³⁺:K+=25:1:1.（4） When Y³⁺:Eu³⁺:Li+=25:1:0.5, the luminescent intensity and the quantum efficiency of the Y₂O₃:Eu³⁺:Li+ phosphor were increased by 67.2% and 53.4% respectively compared with the Y₂O₃:Eu³⁺ phosphor. At this time, Y₂O₃:Eu³⁺:Li+ phosphor was completely acicular, thin and long needle, needle length mainly concentrated in 1.0¹.5 μm. The characteristic diffraction peak of Y₂O₃:Eu³⁺:Li+ phosphor with Y³⁺:Eu³⁺:Li+=25:1:0.5 was fine and sharp, the area of characteristic diffraction peak was the largest and its crystallization property was the best. The best doping ratio of Li+ is Y³⁺:Eu³⁺:Li+=25:1:0.5.（5） When Y³⁺:Eu³⁺:Mg2+=25:1:0.5, the luminescent intensity and the quantum efficiency of the Y₂O₃:Eu³⁺:Mg2+ phosphor were increased by 38.4% and 37.9% respectively compared with the Y₂O₃:Eu³⁺ phosphor. At this time, Y₂O₃:Eu³⁺:Mg2+ phosphor was flaky morphology, and the surface was smooth and the shape was square with the size around 0.5 μm. The characteristic diffraction peak of Y₂O₃:Eu³⁺:Mg2+ phosphor with Y³⁺:Eu³⁺:Mg2+=25:1:0.5 was fine and sharp, the area of characteristic diffraction peak was the largest and its crystallization property was the best. The best doping ratio of Li+ is Y³⁺:Eu³⁺:Mg2+=25:1:0.5.（6） Doping Al³⁺ can make the particle size of phosphor become larger and make the crystallization property become better, but both the luminescent intensity and the quantum efficiency of the Y₂O₃:Eu³⁺:Al³⁺ phosphor were lower than Y₂O₃:Eu³⁺ phosphor. Doping Al³⁺ decreased fluorescent properties of phosphor.