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Study On The Spectra And The Long-lasting Photoluminescence Property Of Ions-doped ZnO-B2O3-SiO2 Glasses And Glass Ceramics

Posted on:2005-05-15Degree:MasterType:Thesis
Country:ChinaCandidate:X H ZhouFull Text:PDF
GTID:2121360122471491Subject:Materials science
Abstract/Summary:PDF Full Text Request
This thesis reviews the history of long-lasting phosphorescent materials comprehensively and presents its recent progress. Long-lasting phosphorescent glass has very wide application and can be used in the fields of laser, optical amplifier , optical communication, energy storage, display etc. It is very useful to carry out the research of high-quality long-lasting phosphorescent glasses.The influence of composition in the host glass on spectra, long-lasting phosphorescent property, photochromism and heat-bleaching property was studied.The phosphorescence mechanism of ZBS: Tb glass was discussed based on the study. At the same time the tentative study of Tb3+, Mn2+ doped ZBS glass ceramics was also carried out. The research was aimed to find the proper host glass and prepare the long-lasting phosphorescent glass ceramics with high quality.The spectra, long-lasting phosphorescent property, photochromism and heat-bleaching property of ZBS: Tb3+ glass with different host composition was systematically investigated by photoluminescence spectra, luminescence decay curves, thermo-luminescence spectra and UV-visible absorption spectra etc. The content of ZnO in the host glass had manifest influence on long-lasting phosphorescent property and photochromism of glass. The research indicates: the increase of ZnO content didn't lead to the formation of new defects but add to the concentration of oxygen ion vacancy associated with Zn2+. After UV-illumination irradiation the concentration of color centers with different depth increased accordingly. Those color centers at deep depth will be stable and mainly responsible for color change, those with shallow depth attribute to the long-lasting luminescence. The intensity and time of afterglow corresponding to 5D4->7F5 transition of Tb3+ were found to be increased with increasing ZnO content. The energy was transferred from the host glass to Tb3+ when the glass was irradiated by UV- illumination. The efficiency of energy-transfer decreased with the increasing of ZnO content and the energy-transfer diminished when the ZnO content was more than 65mol%. The content of SiO2 in the host glasshad slightly influence on long-lasting phosphorescent property of glass.Both the spectra changing character of ZBS glass doped with Tb3+ and that doped with Mn2+ during the heat treatment were investigated, which indicated that the uncontrolled crystallization process would not only result in the weakening of the luminescence intensity but also lead to the displacement of the position of the excitation and emission peaks. Additionally, the influence of crystallization process on the luminescence behavior of Tb + and TiO2 co-doped ZBS glass was also studied, showing that when this kind of glass was excited by ultraviolet, the characteristic spectrum of Tb3+ ion as well as the broad-band emission spectrum of Ti3+ would appear, with the former more manifest than the latter, and that the changing of crystal field of Tb3+ ion would consistently improve the quantum efficiency, companied with the increase of the luminescence intensity of the glass; Besides, it was also shown that when excited by ultraviolet, the broad-band major emission peak of the co-doped glass at 510nm would occur, the intensity of which was continuously increasing as the crystallization process went on.
Keywords/Search Tags:long-lasting phosphorescence, ZnO, ZnO-B2O3-SiO2 glass, energy transfer, glass ceramics, ions doped
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