磷酸盐发光微晶玻璃的制备及发光性质的研究

发布时间：2018-01-20 03:20

本文关键词： 发光微晶玻璃磷酸盐晶相组成晶化温度发光性质　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：白光发光二极管(White Light Emitting Diodes,W-LED)作为一种新型的绿色环保冷光源,具有体积小、寿命长、抗震以及无辐射等优点。目前白光LED主要是由环氧树脂将荧光粉涂敷在半导体芯片上组成,而环氧树脂导热能力差且易老化,降低了白光LED的发光效率和使用寿命。为了避免上述问题,用发光微晶玻璃替代荧光粉的研究引起了人们的极大兴趣。本论文以化学稳定性高、制备温度低、原料廉价易得的磷酸盐微晶玻璃为研究对象,制备并表征了稀土离子激活的CaO-Na2O-P2O5系统磷酸盐微晶玻璃,研究了晶化过程中的物相转变过程及其对微晶玻璃发光性能的影响,分析了Eu~(3+)、Tb~(3+)在微晶玻璃中的发光行为及掺杂浓度对发光性质的影响,对比研究了相同组成的磷酸盐玻璃和微晶玻璃的发光强度。采用熔融淬冷和整体析晶法在不同晶化温度下制备了Eu~(3+)激活的CaO-Na2O-P2O5系统磷酸盐发光微晶玻璃,用X射线衍射和荧光光谱分析分别研究了磷酸盐发光微晶玻璃的物相组成和发光性质,分析了晶化过程中的物相转变过程,考察了热处理制度对磷酸盐微晶玻璃物相组成和发光性质的影响。研究结果表明,所制备得到的微晶玻璃具有良好的透明度和荧光效果,其晶相成分主要含有焦磷酸钙、磷酸钙、过磷酸钙、磷酸钙钠等相,物相转化趋势为Ca3(PO4)2→Ca2P6O17→Ca2P2O7。在393 nm紫外光的激发下,微晶玻璃呈现红色光发射,发光强度和色度与晶化温度、晶相成分和样品透明度之间有较强的关联性。随着晶化温度的升高,微晶玻璃发射光谱的红橙比(614nm红色光与587nm橙色光的强度比值)整体呈增大趋势,表明Eu~(3+)在晶化过程的新生物相中以占据非中心对称格位为主。Eu~(3+)在CaO-Na2O-P2O5系统磷酸盐发光玻璃/微晶玻璃中的发光属于Eu~(3+)的5D0→7FJ(J=1,2,3,4)特征跃迁,以位于614 nm的红色光发射为主,其激发光谱中位于393 nm和465 nm处的激发峰表明该类材料可以被LED的长波紫外光芯片或蓝光芯片有效激发。Tb~(3+)在CaO-Na2O-P2O5系统磷酸盐发光玻璃/微晶玻璃中的发光属于Tb~(3+)的5D4→7FJ(J=6,5,4)特征跃迁,以位于545 nm的绿色光发射为主,其激发光谱中位于372 nm和483 nm处的激发峰表明该类材料可以被LED的长波紫外光芯片或蓝光芯片有效激发。在CaO-Na2O-P2O5系统磷酸盐发光玻璃/微晶玻璃中掺入不同浓度的Eu~(3+)或Tb~(3+),其激发光谱和发射光谱的峰位置和谱线形状基本保持不变。在掺入量为1~6 mol%的范围内,随着激活离子Eu~(3+)或Tb~(3+)浓度的升高,磷酸盐发光玻璃或微晶玻璃的发射强度均不断增强,表明在该浓度范围内未出现稀土离子发光的浓度猝灭现象。对比相同组成的发光微晶玻璃和发光玻璃的荧光光谱发现,Eu~(3+)、Tb~(3+)激活的发光微晶玻璃的发光强度均高于相同组成的发光玻璃,表明CaO-Na2O-P2O5系统磷酸盐微晶玻璃是一类比相同组成磷酸盐玻璃更好的发光材料基质。
[Abstract]:White Light Emitting Diodes-W-LED (White Light Emitting Diodes-W-LED) is a new kind of green green cold light source with small size and long life. At present, white LED is mainly composed of epoxy resin coating phosphor on semiconductor chip, while epoxy resin has poor thermal conductivity and is easy to aging. The luminescence efficiency and service life of white LED have been reduced. In order to avoid the above problems, the study of using luminescent glass-ceramics instead of phosphors has aroused great interest. In this paper, the chemical stability is high. Phosphate glass-ceramics with low temperature and cheap raw materials were prepared and characterized by rare earth ions activated phosphate glass-ceramics in CaO-Na2O-P2O5 system. The phase transition process and its effect on the luminescence properties of glass-ceramics during crystallization were studied. The Eu~(3) was analyzed. The luminescence behavior of Tb~(3 in glass-ceramics and the influence of doping concentration on the luminescence properties. The luminescence intensity of phosphate glass and glass-ceramics with the same composition were studied. Eu~(3 was prepared by melt quenching and crystallization at different temperatures. Activated CaO-Na2O-P2O5 system phosphate-luminescent glass-ceramics. The phase composition and luminescence properties of phosphate-luminescent glass-ceramics were studied by X-ray diffraction and fluorescence spectroscopy. The effects of heat treatment on the phase composition and luminescence properties of phosphate glass-ceramics were investigated. The results show that the prepared glass-ceramics have good transparency and fluorescence properties. The crystalline phase consists of calcium pyrophosphate, calcium phosphate, calcium superphosphate, sodium calcium phosphate and so on. The trend of phase transformation is Ca3(PO4)2. 鈫扖a2P6O17. 鈫扷nder the excitation of 393 nm ultraviolet light, the glass-ceramics exhibit red light emission, luminescence intensity, chromaticity and crystallization temperature. There is a strong correlation between the crystalline phase composition and the transparency of the sample, with the increase of crystallization temperature. The ratio of red orange (614nm) to 587nm (the ratio of red orange to 587 nm orange) of glass-ceramics emission spectra showed an increasing trend as a whole. It is shown that Eu~(3) occupies the dominant non-centrosymmetric lattice in the new biological phase of the crystallization process. The luminescence in phosphate luminescent glass / glass-ceramics in CaO-Na2O-P2O5 system belongs to 5D0 of Eu~(3). 鈫扵he red light emission at 614 nm is the main red light emission. The excitation peaks at 393nm and 465nm in the excitation spectrum indicate that this kind of material can be effectively excited by LED's long-wave ultraviolet or blue chip. Luminescence in phosphate luminescent glass / glass-ceramics in CaO-Na2O-P2O5 system belongs to 5D4 of Tb~(3). 鈫扵he green light emission at 545 nm is the main green light emission. The excitation spectra are located at 372 nm and 483 nm. The excitation peak at Nm indicates that this kind of material can be effectively excited by long wave ultraviolet or blue light chip of LED. Different kinds of phosphate-luminescent glass / glass-ceramics are doped in CaO-Na2O-P2O5 system. Concentration of Euconium (. 3) or Tb~(3). The peak position and spectral line shape of the excitation and emission spectra remained basically unchanged, and the doping amount was 1 ~ 6 mol%. The emission intensity of phosphate-luminescent glass or glass-ceramics increased with the increase of the concentration of activated ion Eu~(3) or Tb~(3. The results show that there is no concentration quenching phenomenon of rare earth ion luminescence in this range. The fluorescence spectra of luminescent glass-ceramics and luminescent glass with the same composition have been found. The luminescence intensity of the luminescent glass-ceramics activated by Tb~(3 was higher than that of the luminescent glass with the same composition. It is shown that CaO-Na2O-P2O5 system phosphate glass-ceramics is a better luminescent material matrix than the same composition phosphate glass.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN312.8;TQ171.733

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