【作者】 韩国才；

【导师】 王育华；

【作者基本信息】 兰州大学 ， 材料物理与化学， 2010， 博士

【摘要】 以磷酸盐为基质的发光材料因其具有良好的化学稳定性、合成温度低、制备简单、量子效率高等特点,成为真空紫外(VUV)荧光粉基质的首选,研究Dy3+激活的磷酸盐的发光性质不仅有科学方面的意义,而且在实际应用方面也有潜在的价值。因此本论文制备了Dy3+离子掺杂的稀土正磷酸盐LnPO4 (Ln=Gd, La, Y)受到真空紫外激发时的发光特性。其次,制备了Dy3+离子掺杂的KCaYPO4, CaLaP3O10和]Ln(PO3)3:Dy3+(Ln=La,Gd,Y)多种荧光材料,并分别考察了它们在真空紫外激发下的发光性能。主要结论如下：1.研究了Dy3+掺杂的系列正磷酸盐的发光性能。采用水热法合成了LnPO4:Dy3+(Ln=Gd,La,Y)粉末样品,研究了它们在真空紫外激发下的发光性能。通过光谱分析,发现稀土正磷酸盐LnPO4:Dy3+(Ln= Gd, La, Y)不仅能够高效吸收真空紫外辐射,并能向激活剂离子传递激发能,从而使LnPO4 (Ln=Gd, La, Y)具有较高的发光强度,其中以Gd0.92PO4:0.08Dy3+的发光强度最高,是一种潜在的无汞荧光灯用发光材料。计算了La PO4和Y PO4的电子结构,表明La PO4和Y PO4都是间接跃迁材料。2.研究了Dy3+掺杂的系列多磷酸盐的发光性能。采用固相法合成了KCaYPO4:Dy3+粉末样品,研究了它们在真空紫外激发下的发光性能。发现KCaYPO4:Dy3+中KCaPO43+基团能够有效地吸收162 nm、185 nm和195 nm附近的激发能,发光位于白光区,在单一体质中实现白光发射,是一种有潜质的白光材料。3.研究了Dy3+掺杂的系列多磷酸盐的发光性能。采用固相法合成了CaLaP3O10:Dy3+粉末样品,研究了它们在真空紫外激发下的发光性能。发现CaLaP3O10:Dy3+中CaP3O103+基团能够有效地吸收120 nm、130 nm和171 nm附近的激发能,发射较强白光,是一种较好的基质材料并具有一定的应用潜力。4.研究了Dy3+掺杂的系列多磷酸盐的发光性能。采用固相法合成了Ln(PO3)3:Dy3+(Ln=La,Gd,Y)粉末样品,研究了它们在真空紫外激发下的发光性能。发现Ln(PO3)3:Dy3+(Ln= La, Gd, Y)中(PO3)33-基团能够有效地吸收158nm、182 nm和199 nm附近的激发能,虽然能够得到色纯度很好的白光,但是发光强度不高。并计算了La(PO3)3的电子结构,表明La(PO3)3是直接跃迁材料。更多还原

【Abstract】 Phosphates are considered as good host materials for the vacuum ultraviolet (VUV) phosphors due to good chemical stable, low synthesizing temperature, simple preparing conditions and high quantum efficency. In this paper, we investigated the luminescent properties of phosphates activated by Dy3+, which is significative both on the scientific research and in practice.Firstly, we have synthesized Orthophosphates by a mild hydrothermal method and investigated their photoluminescence (PL) spectra under VUV excitation. Secondly,_we also investigated the photoluminescent properties of Dy3+ doped other phosphate phosphors (KCaYPO4, CaLaP3O10 and Ln(PO3)3 (Ln=La, Gd, Y)) to evaluate them to be or not for VUV phosphors. The main conclusions are following:1. we have prepared LnPO4 (Ln=Gd, La, Y) using a mild hydrothermal method and investigated their luminescent properties under VUV excitation. The results indicate that Rare earth orthophosphates LnPO4(Ln=Gd, La, Y)show not only high efficiency of VUV absorption but also high efficiency of energy transfer from the host to the luminescent centers, such as Dy3+ ions. So LnPO4 (Ln= Gd, La, Y):Dy3+ phosphors exhibit high luminescence efficiency, especially the luminescent intensity of Gd0.92PO4:0.08Tb3+ phosphor. Moreover, we have calculated the electronic structure of LaPO4 and YPO4 and analyzed their energy band structre and density of states.2. we have prepared KCaYPO4:Dy3+using solid state reaction and investigated their luminescent properties under VUV excitation. It can be found that the KCaPO43+ groups of KCaYPO4:Dy3+ can absord the energy around 162 nm,185 nm and 195 nm. For Dy3+ doped KCaYPO4, the KCaPO43+ groups can absorb the excited energy in the VUV region.3. we have prepared CaLaP3O10:Dy3+ using solid state reaction and investigated their luminescent properties under VUV excitation. It can be found that the CaP3O103+ groups of CaLaP3O10:Dy3+ can absord the energy around 120 nm,130 nm and 171 nm. For Dy3+ doped CaLaP3O10, the CaP3O103+ groups can absorb the excited energy in the VUV region. 4. we have prepared Ln(PO3)3:Dy3+(Ln= La, Gd, Y) using solid state reaction and investigated their luminescent properties under VUV excitation. It can be found that the (PO3)33+ groups of Ln(PO3)3:Dy3+(Ln= La, Gd, Y) can absord the energy around 158 nm, 182 nm and 199 nm. For Dy3+ doped Ln(PO3)3 (Ln= La, Gd, Y), the (PO3)33+ groups can absorb the excited energy in the VUV region.更多还原