【作者】 李叶洲；

【导师】 王育华；

【作者基本信息】 兰州大学 ， 材料物理与化学， 2011， 博士

【摘要】 针对目前照明和信息显示器件用新型荧光粉的发展需要,本论文选取了几种典型的含氧酸盐作为基质材料,制备了以Eu2+、Tm3+、Ce3+、Tb3+、Dy3+等作为激活离子的一种典型磷酸盐、三种硅酸盐和一种锆酸盐荧光粉,并探讨了它们在白光LED以及PDP显示器领域的潜在应用。这一系列研究成果对于探索新型氧化物发光材料的发光性能、推动其在照明和显示器领域的应用具有重要的基础意义和实用价值。第一,在具有典型磷钠钙石结构的β-NaCaPO4基质中掺入蓝光激活离子Tm3+,并通过对其UV-Vis吸收光谱、UV和VUV激发和发射光谱的研究,首次对β-NaCaPO4:Tm3+的UV-VUV发光性质进行了探讨,同时对各个光谱的峰位进行了归属。结果发现,β-NaCaPO4:Tm3+在UV和VUV激发下具有色纯度较好的蓝光发射,样品的热稳定性能明显优于商用蓝粉,是一种潜在的新型PDP用蓝色荧光粉。第二,通过调节和控制起始原料中的Al/Si比例,成功制备得到了具有BaAl2O6衍生结构的Ba13Al22Si10O66的单相样品。首次在无还原气氛的制备条件下得到了具有Eu2+特征发光的Ba13Al22Si10O66：Eu2+白色发光材料,并发现其具有蓝白色余辉,该材料不仅可以作为白光LED用发光材料,而且是一种新型长余辉材料。另外Ba13Al22Si10O66：Ce3+和Ba13Al22Si10O66：Tb3+可以在UV激发下产生良好的发光。然而在VUV区域,Ba13Al22Si10O66：Eu2+,Ce3+,Tb3+的发光很弱,没有作为PDP发光材料的潜质。第三,在硅酸盐基质Li4SrCa(Si04)2掺入了几种典型稀土离子：Eu2+、Tm3+、Ce3+、Dy3+,并首次探索了它们各自的UV-VUV发光性质。Li4SrCa(SiO4)2:Eu2+在UV激发下可以产生良好的蓝紫色发射,是一种有潜力的白光LED用蓝色发光材料；Li4SrCa(Si04)2:Tm3+在UV和VUV激发下都可以产生Tm3+的特征发射,表现为色纯度较好的蓝色发光,同时其VUV最强激发峰与Xe气体放电的激发波长匹配较好,具有作为PDP发光材料的潜力；Li4SrCa(Si04)2:Ce3+在UV和VUV激发下都可以呈现出Ce3+的5d-4f特征蓝色发射,但就色纯度而言,UV激发下的样品更适合被白光LED采用；Li4SrCa(Si04)2:Dy3+在UV和VUV下的发光都为Dy3+的特征f-f发射,其发光颜色偏黄,需要进一步改善。第四,对稀土焦硅酸盐β-Y2Si2O7尝试单掺Ce3+、Tb3+以及共掺Ce3+和Tb3+,在研究了它们各自的UV-VUV发光性质的基础上,首次探索了两离子在VUV区域的能量传递过程,考察了共掺样品在PDP领域的潜在利用价值。第五,对双钙钛矿结构的锆酸盐CaZrO3进行了Dy3+、Tm3+的单掺杂以及Dy3+、Tm3+的共掺杂,同时考察了共掺样品在UV区域内的Tm3+和Dy3+的能量传递过程,探索了其在白光LED领域的潜在应用。更多还原

【Abstract】 Aiming at the demand for the novel phosphors utilized in illumination and display, by selecting several typical oxysalts as host materials, a phosphate, three silicates and a zirconate activated by Eu2+, Tm3+, Ce3+, Tb3+, Dy3+ ions et al. were synthesized, and their potential possibility as novel UV-LED and PDP phosphors were first explored and discussed in this paper. From the angle of basic theory and practical value, the results abovementioned would significantly contribute to the exploration of the photoluminescent properties for the new kinds of oxysalt phosphors and the promotion of the application in illumination and display fields.First, merrillite structuredβ-NaCaPO4 host was doped by blue-emitting ion Tm3+. The UV-VUV photoluminescent properties ofβ-NaCaPO4:Tm3+ was first investigated by UV-Vis absorption spectra, excitation and emission spectra in UV and VUV region, and all the peaks in the curves were attributed. The results indicated thatβ-NaCaPO4:Tm3+ could generate blue light with good color purity by UV and VUV excitation, the thermal stability of which was evidently better than the commercial blue phosphor. The phosphor could be a new potential blue phosphor for PDP.Second, single phase of Ba13Al22Si10O66 with the derivative of BaAl2O6 structure was successfully prepared by adjusting and controlling the ratio of Al/Si in raw materials, and the photoluminescent properties of the host activated by Eu2+, Ce3+ and Tb3+ in UV-VUV region was explored. White-emitting phosphor Ba13Al22Si10O66:Eu2+ with the characteristic luminescence of Eu2+ was first obtained without reducing atmosphere and was proved to have bluish white long afterglow. This phosphor could be adopted by white LED and was a new potential long afterglow phosphor. Furthermore, Ba13Al22Si10O66: Ce3+ and Ba13Al22Si10O66: Tb3+ could generated intense luminescence by UV excitation. However, the three phosphors Ba13Al22Si10O66: Eu2+, Ce3+, Tb3+ hardly emitted light in VUV region, which were not proper to serve as PDP phosphor.Third, several representative rare-earth ions (Eu2+, Tm3+, Ce3+, Dy3+) were introduced in the silicates host Li4SrCa(SiO4)2, and their photoluminescent properties were first discussed in UV-VUV region. Li4SrCa(SiO4)2: Eu2+ could generate bluish purple emission by UV excitation, which was a potential blue-emitting phosphor utilized by white LED. Li4SrCa(Si04)2:Tm3+ emitted the characteristic emission of Tm3+ by UV and VUV irradiation, which was blue light with good color purity. The strongest VUV excitation peak of the sample matched well with the wavelength that the Xe gas discharged; hence it could be suitable serve as PDP phosphors. By UV and VUV excitation, Li4SrCa(SiO4)2:Ce3+ could produce 5d-4f characteristic emission of Ce3+ by both UV and VUV excitation, however, apropos to the color purity, the sample under UV excitation was proper to be adopted by white LED. The luminescence of Li4SrCa(SiO4)2: Dy3+ generated the characteristic f-f emission of Dy3+ by UV and VUV excitation, which was yellowish and needed to be improved.Fourth, the UV-VUV photoluminescent properties of rare-earth focal silicateβ-Y2Si2O7 doped with Ce3+, Tb3+ or Ce3++Tb3+ were studied, and the energy transfer process of the two ions in VUV region were first explored. Hence the potential possibility for it to serve as PDP phosphor was valued.Fifth, double-perovskite-structured CaZrO3 was doped with Dy3+, Tm3+ and Dy3++Tm3+. The energy transfer process of Dy3+ and Tm3+ in co-doped samples was investigated, and the co-doped samples were potentially utilized in white LED.更多还原