Re-doped Aluminum Acid Strontium Long Afterglow Materials And Characterization Of The Performance

Long--lasting aftergrow materials are one of the important light-·light transformation and energy-savingmaterials. These materials find extensive applications in many fields such as traffic signs,interior decoration and light sources.Rare earth ion activated aluminate materials are very important Long--lasting aftergrow materials, which always display some individual applications because of their unique physical and chemical properties. However, this kind of materials also has their unresolved shortcomings mainly behaving as few colors, large crystal particles, and so on. As a result, their application areas have been sevrely limited. In this dissertation, new synthesis methods and technologies were investigated to deal with those meet problem and a kind of high-quality materials of fine grain size, good luminescent efficiency,good afterglow performances is obtained.We have four part research in this paper.In the first part, the recent research on Aluminate-system Long Afterglow Materials (ALAMs) was summarized, characterization and formation mechanism of oxide-system Long Afterglow Materials were pointed out, and the potential applications of ALAMs were discussed .In the second part, SrAl2O4:Eu2+,Dy3+ system Long Afterglow Materials was prepared by the sol-gel method, and add different amounts of boric acid to reduce the sintering temperature samples. Use of X-ray diffraction (XRD) confirmed that the product was of the strontium-rich monoclinic SrAl2O4 phase. SEM observations showed irregular shape of its spherical. The excitation and emission spectrums of the products were analyzed by fluorescent photometer, their emission spectrum is composed of continuous broad band spectra from 570 to 630 nm, the emission spectrum is composed of continuous broad band spectra from 240 to 480 nm. The condition for synthesizing ALAMs is following: the calcination temperature is 700oC, and the pH value for this reaction is about 4.5.In the third part, Rod-like SrAl2O4:Eu2+, Dy3+ long afterglow phosphor emitting green light was synthesized by using the mixed solution of urea and nitrate as reactants at 600°C in air atmosphere. Phase composition, morphology, excitation spectrum, emission spectrum as well as the decay curve of the phosphor were investigated. The results showed that the rod-like SrAl2O4:Eu2+, Dy3+ belongs to a monoclinic phase, and that the green-emission band with the peak at 512 nm was observed with ultraviolet excitation. The duration time is 6 hours long. The influence of urea and high-temperature calcination on the luminescent property of phosphor was also investigated.In the last part, Ca12Al14O33:Eu2+, Dy3+ long afterglow phosphor emitting blue light was also synthesized by using the mixed solution of urea and nitrate as reactants at 500°C in air atmosphere. Phase composition, morphology, excitation spectrum, emission spectrum as well as the decay curve of the phosphor were investigated. The results showed that the Ca12Al14O33:Eu2+, Dy3+ belongs to a body-centered cubic structure, and that the blue-emission band with the peak at 440 nm was observed with ultraviolet excitation(280-420nm). The duration time is 110 second long.