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The Study On The Polychrome Long Afterglow Phosphors Activated By Rare Earth Elements

Posted on:2004-03-07Degree:MasterType:Thesis
Country:ChinaCandidate:S C ZhuFull Text:PDF
GTID:2121360122961178Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
A new type of long afterglow phosphor SrAl2O4:Eu,Dy, which can be used to night illumination and decoration, has been synthesized and got rapid development in the middle of 20th century. The aluminates are used as the base and the rare earth materials are used as the luminescence center and trap center. The excitation resource can be visible light and man-made light. This type of long persistent phosphor has the advantages of innocuity, no radioactivity, high luminescence, long duration and no need of electricity, so it can be regarded as high efficiency solid display material. With the wide application of this material, the single yellow-green color can no longer satisfy the demand. In this dissertation, these long afterglow phosphors were prepared by solid-state reaction. By this method, some further study on the luminescence properties of SrAl2O4:Eu,Dy were carried out. The effect of H3BO3 was discussed in detail, and the luminescence and aferglow time was increased. The stability of this material was studied and it needs coating processing in application. Then by changing the base, activator, flux and reaction condition, we studied different phosphors based on the aluminates, silicates, CaTiO3 and Y2O2S in detail, and obtained the best stoichiometry and preparation of these phosphors with the colors of red, red and orange, yellow-green, blue-green, cyan and blue-purple. The luminescence characteristics of these phosphors were investigated, and the luminescence mechanisms were also discussed.Through this dissertation, the best preparation methods of these polychrome long afterglow phosphors can be provided for large-scale industrial production. And the application of these type of long afterglow will be expanded.
Keywords/Search Tags:polychrome, long afterglow, SrAl2O4:Eu, Dy, crystal structure, trap
PDF Full Text Request
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