| In this paper, the current situation and development of phosphors were summarized, Especially, those of the long lasting phosphorescence. The current situation, development, characteristic of phosphors, preparation and application prospect of phosphorescence system of alkaline earth aluminate were emphasized elaborately. Its optical properties were compared with those of other phosphorescent systems.Long lasting phosphorescence of alkaline earth aluminate doped with rare earth as a non-radioactive phosphor has excellent luminescent property and not environmental pollution in the process of preparation, so it has wide application prospect. However, its cost is too high so that its application is restricted seriously. In this paper, new method and technique of preparation were studied in order to decrease the cost.1 When we have used the self-prepared superfine aluminum oxide( purity 99.9%, granularity 1.499um), self-prepared extra-purified carbonate strontium, europium oxide and dysprosium oxide as raw materials, boric acid(analysis purity, 0.13mol fraction) as flux, active carbon(analysis purity) for the ratio of 1:5 and sub-determine oxide(industrial purity) for the ratio of 5:1 as reductant, under the condition of sintering for 2 h at 1350癈 and naturally lowering the temperature, high-quality phosphor product ?SrAhO4:Eu,Dy can be prepared. The cost is lower and the process which has not been reported in literatures is simplified. In order to study the influence of the granularity of aluminum oxide on optical properties of phosphor, superfine aluminum oxide was prepared by combustion synthesis with igniting temperature at 500C and the actual quality of urea for 1.5 times as much as theoretic quality, the granularity of prepared product is up to 1.499nm which has not been reported in literature.2 In order to decline the phosphor's cost, a new synthetic method combustion synthesis were used to prepare high-quality and cheap phosphorescence MgSr6Al2O3:Eu,Dy, and used Mg Al instead of Sr respectively in substrate in the process. Both phosphors and their process have not been reported in literatures yet. First the new long lasting phosphorescence ?MgSrAl2O4:Eu,Dy was prepared by combustion synthesis at 600 with the ratio of Mg/Sr for 1. Then used the self-prepared extra-purified nitrate aluminum and nitrate strontium as raw materials, under the condition of taking the combination of borate acid(0.12 mol fraction) and AlF3(0.04mol fraction) as flux, the quality of urea for 2 times as much as theoretic quality as reductant, doping with Eu for the ratio fraction of 0.004 and the quality of Dy3+ for 10 times asinmuch as that of Eu, a new long lasting phosphorescence ?SrO 6Al2O3:Eu,Dy was prepared by combustion synthesis at 600 of igniting temperature in the furnace. This luminescent intensity closed to that by solid-state synthesis and its cost decreases in a heavy degree. ...It was found that the phosphor's exciting spectrum and emission spectrum is broad spectrum by measuring, according with the reported literatures. The exciting peak wavelength of Sr370nm respectively. Emission peak wavelength of them is 530nm, 510nm, 520nm respectively. Their luminescent declining matches with the formula I = n for 0.630, 0.595, 0.581; c for 173, 157, 135 respectively), afterglow time is more than 12 h (0.38mcoVm2) and their afterglow brightness is 0.4 mcd/m2, 0.45 mcd/m2, 0.52 respectively after 12 h.The principle of luminescence is analyzed simply in this paper. |
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