| ABSTRACT: The luminescent material Y2O3: Eu3+has an advantage of high quantum efficiency, well stability and high colorpurity. Y2O3:Eu3+is the preferred red component in trichromatic phosphors. In recent years, red phosphor Y2O3:Eu3+is widely used in flat panel display, detection and medical testing. As we know nano-particle has a high specific surface area, and the quenching effect caused by defects and impurity ions on the surface will also affect the luminescence, thus, surface modification is used to improve the light-emitting.The main researches are as follows:First of all, spherical nano-particles of Y2O3: Eu3+were prepared by homogeneous precipitation, and then XRD and SEM is used to test and analysis the sample.With the control of the urea concentration, reaction time, reaction temperature, particle size of thenanoparticles shows a certain law. Finally an optimal synthesis condition for synthesizing the nano-particles is identified.On this basis, the nuclear surface was coated by shell material Lu2O3. In order to prove the successful coating, analysis of the following tests has been done. Compared to the uncoated sample, the coated material has a higher luminescence emission. SEM tests show that the coated sample’s particle size is slightly larger. A series of HRTEM results, providing further proof to the successful coating, show that the surface of the core Y2O3is coated of Lu2O3. The decay curves indicate that the sample with core/shell structure has a longer decay time.Core-shell Y2O3:Eu3+@Lu2O3with different coating thickness was synthesized by adjusting the ratio of the core and shell. The optimal coating thickness is identified by testing the spectroscopy, XRD,and decay times. At last, the relationship between the coating thickness of the core-shell nano-materials and the decay times was discussed. The decay time presents different variation with the increasement of the coating thickness. |
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