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钛酸钙镨红色长余辉发光粉体和薄膜的制备及性能研究
Researches on Synthesis and Photoluminescence of the Red Long Persistent Phosphors and Films CaTiO3: Pr3+
【作者】 田艳红;
【导师】 崔彩娥;
【作者基本信息】 太原理工大学 , 凝聚态物理, 2011, 硕士
【摘要】 长余辉发光材料是一种关闭光源后仍能持续长时间发光的新型功能材料,被广泛应用于紧急照明、军事、工艺美术、光信息存储、成像显示和辐射探测等领域,其形态由粉末扩展到薄膜、玻璃、陶瓷等。但是作为三基色之一的红色长余辉发光材料的发光性能还不能达到实际应用的要求,在一定程度上抑制了长余辉材料的应用。所以研发新型红色长余辉发光材料成为当前急需解决的问题。CaTiO3:Pr3+红色长余辉发光材料具有良好的稳定性及其色坐标值(x=0.68,y=0.31)与NTSC的理想红色坐标(x=0.67,y=0.33)非常接近,引起了人们广泛的关注。本文旨在通过新的溶胶凝胶燃烧法的工艺制备该类红色长余辉发光材料,以期研究开发一种廉价、无污染的高效节能型红色长余辉发光材料。本工作在前人实验研究CaTiO3:Pr3+红色长余辉发光材料的基础上,研究发现了能够利用溶胶凝胶燃烧法制备CaTio3:Pr3+红色长余辉发光材料。这一发现克服了用传统的高温固相法制备发光材料煅烧温度高、制备的样品颗粒尺寸大的缺点,并且避免了溶胶凝胶法制备发光材料时湿凝胶制备干凝胶的过程,缩短了生产周期,达到了节时、节能的效果。本文首次采用溶胶凝胶燃烧法以CaTiO3为基质、硝酸锌为助溶剂、碳酸钠为电荷补偿剂成功制备了Ca0.8Zn0.2TiO3:Pr3+,Na+纳米红色长余辉发光材料。利用XRD、SEM、荧光分光光度计、热释光谱仪和照度计研究了Pr3+含量、烧结温度、恒温时间、升温速率对样品物相、形貌以及发光性能的影响。结果显示,样品的激发峰为328 nm,发射峰为613 nm,余辉时间最长达10Omin(≥mcd/m2)经过对比实验,确定了制备Ca0.8Zn0.2TiO3:Pr3+,Na+纳米红色长余辉发光材料的最佳条件:名义组分Ca0.796Zn0.2TiO3:0.002Pr3+0.002Na+、煅烧温度800℃、恒温时间3h、升温速率5~7℃/min。近年来长余辉发光薄膜被提出可应用于场发射显示器件,本文将溶胶凝胶燃烧法制备Ca0.8Zn0.2TiO3:Pr3+,Na+的最佳参数应用于制备Ca0.8Zn0.2TiO3:Pr3+,Na+长余辉发光薄膜。利用XRD、SEM、荧光分光光度计和照度计研究了烧结温度、溶胶浓度、提拉速度、薄膜层数对薄膜物相、形貌以及发光性能的影响。结果显示,样品的激发峰为328 nm,发射峰为614 nm,较粉体发生了1 nm的红移,余辉时间最长达130s(≥mcd/m2)。经过对比实验,确定了制备Ca0.8Zn0.2TiO3:Pr3+,Na+纳米红色长余辉发光薄膜的最佳条件:煅烧温度850℃、溶胶浓度0.25~0.3mol/L、提拉速度7.36~10.36cm/min(10~13V)、薄膜层数8层。
【Abstract】 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.
【Key words】 Ca0.8Zn0.2TiO3:Pr3+; Na~+; phosphor; films; red long afterglow; sol-gel combustion;