| The long afterglow phosphor is a new functional material that can illuminate for a long time after the lamp-house is closed. This material has been applied in lots of domains such as emergent illumination, military affairs, industrial arts, optical data storage, imaging showed and radiation detection etc. The type was expanded from powder to film, glass, ceramics, etc. But as one of primary colors, the red long persistent materials cannot achieve actual application requirements yet. The application is restrained by the deficiency of the red long afterglow phosphor. So research and development of new red long afterglow phosphorescent materials become the urgent problems to be resolved. The red long afterglow phosphor CaTiO3:Pr3+ has good stability and high quality red emission with chromaticity coordinates positioned at x=0.680 and y=0.311, which are very close to those of the NTSC ideal red emission (x=0.67, y=0.33). In this paper, calcium titanate phosphors were prepared by a new method of sol-gel-combustion process in order to research and develop a sort of cheap, environmental friendly and high-efficient red long afterglow phosphors materials.This work was expanded on the basis of predecessors's experimental result on CaTiO3:Pr3+ red long-glow phosphor. We found that the red long afterglow luminescent nanomaterial Ca0.8Zn0.2TiO3:Pr3+,Na+ can be synthesised by sol-gel combustion method.This discovery overcomes high calcining temperature and big particle size when CaTiO3:Pr3+ phosphor was synthesised by traditional high temperature solid phase reaction, and avoids process from wet gel to dry gel. This method shorten the production cycle,and save the time and energy.The red long afterglow luminescent nanomaterial Ca01.8Zn0.2TiO3:Pr3+,Na+ was first synthesised by sol-gel combustion method with CaTiO3 for matrix, zinc nitrate for cosolvent, sodium carbonate for charge compensation agent. Effects of Pr3+ content, calcination temperatures,constant temperature time and heating rate on the crystal characteristics, surface morphology and luminescent properties of the samples were investigated using XRD, SEM, fluorescence spectrophotometer and thermally stimulated spectrometer. Results indicate: Sample excitation peak centered at 328nm and appears a single peak centered at 613nm. The longest afterglow time is 10min(≥1mcd/m2). Through contrast test, the optimum condition of manufacturing red long afterglow luminescent nanomaterial Ca0.8Zn0.2TiO3:Pr3+,Na+ is determined:The nominal composition is Ca0.796Zn0.2TiO3:0.002Pr3+,0.002Na+;Calcination temperature is 800℃; Constant temperature time is 3h;Heating rate is 5～7℃/min.In recent years long afterglow luminescent film which can be applied to field emission display device was proposed. Long afterglow luminescent Ca0.8Zn0.2TiO3:Pr3+ was synthesized in this paper, on the basis of optimum condition of synthesizing long afterglow luminescent film Ca0.8Zn0.2TiO3:Pr3+,Na+ by sol-gel combustion method. Effects of calcination temperatures, sol concentration, tiras speed and the number of film layer on the crystal characteristics, surface morphology and luminescent properties of the samples were investigated using XRD, SEM, fluorescence spectrophotometer and thermally stimulated spectrometer. Results indicate that sample excitation peak centered at 328 nm, emission peak at 614 nm, 1nm redshift is happened compared to previous powder, and the longest of afterglow time reach 130s. Through contrast experimental, we find the optimum condition of synthesizing Ca0.8Zn0.2TiO3:Pr3+,Na+ long afterglow luminescent film.Calcination temperatures is 850℃,sol concentration is 0.25～0.3mol/L, tiras speed is 7.36～10.36cm/min(10～13V),and the number of film layer is 8. |
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