Synthesis And Luminescent Properties Of Silicate Long Afterglow Phosphors Actived By Europium

With the development of long afterglow materials, a new generation of long afterglow materials, which were synthesized in 1990s, receive remarkable attention because of their better luminescence properties. At present, the interest of studies is mainly focused on the system of aluminate. Alternatively, the silicated materials are considered to be a very promising long afterglow materials because they have good stability, they are cheap and easy to obtain, and their calcination temperature is lower than that of aluminum system. Further studies of the silicate system is still required, which stands particularly in what concerns the species enrichment, the glowing effect improvement and practicality.Firstly, The blue afterglow phosphor Sr₂MgSi₂O₇:Eu²⁺,Dy³⁺ was prepared by the high temperature solid-state method. We investigated the influences of synthsis calcining temperature, holding time, rare earth ions doping concentration and the concentration of H3BO3 on luminescence properties were systematic studied. We determined the best proportion of the luminescent materials that it can make the luminescence for more than 20 h.Secondly, The blue afterglow phosphor Sr₂MgSi₂O₇:Eu²⁺,Dy³⁺ was prepared by sol-gel and combustion method, respectively. Compared to the high-temperature solid-state method, the samples with these two methods have the lower luminescence. But the calcining temperature of sol-gel method is low about 100℃than that of the high-temperature solid-state method, and the combustion method is saving energy, low costs, simple operation and synthsis rapid. But the luminescent properities of the materials are low. So, this method for further needs to improvement and perfection.Thirdly, We analyzed systematically the influences of all the factors to silicate long afterglow materials. And the mechanism of silicate long afterglow materials were analyzed through used the mechanism of aluminum long afterglow materials for reference.Fourthly, The blue-violet afterglow phosphor Ca₂Al₂SiO₇:Eu²⁺, Nd³⁺ was prepared by the high temperature solid-state method for the first time. We investigated the influences of synthsis calcining temperature, holding time, rare earth ions doping concentration and the concentration of H₃BO₃ on luminescence properties were systematic studied. And through compared to Ca₂Al₂SiO₇:Eu²⁺, we studied on the use of Eu²⁺ and Nd3+ in the materials.