【作者】 李杰；

【导师】 王育华；

【作者基本信息】 兰州大学 ， 材料物理与化学， 2010， 硕士

【摘要】 三基色荧光粉的研究对提高等离子平板显示器(PDP)的显色性至关重要。目前,被认为显色效果最好,能作为PDP用的商业红色荧光粉的材料是(Y,Gd)BO3：Eu3+,但是(Y,Gd)BO3：Eu3+还存在着发光效率低、色纯度较差的问题。针对上述问题,本文从材料改性和理论两个方面开展工作,一方面对(Y,Gd)BO3：Eu3+进行掺杂改性研究,合成系列新型荧光粉,研究其发光性质；另一方面通过对YBO3的电子结构进行模拟计算,对影响荧光粉激发性能的因素进行评价,结合(Y,Gd)BO3：Eu3+的最佳配比,探索了产业化制备的最佳工艺条件。在对(Y,Gd)BO3：Eu3+的掺杂改性研究中,首先从进一步提高发光强度考虑,我们采用高温固相法制备Y0.75-xGdxAl0.10BO3：0.10Eu3+,0.05R3+(R=Sc,Bi；0.00≤x≤0.45)系列样品,研究它们在紫外(UV)和真空紫外(VUV)激发下的发光性能。结果表明,随着Al3+、Sc3+、Bi3+和Gd3+离子的掺杂,(Y,Gd)BO3：Eu3+的发光强度和色纯度都有了不同程度的提高。因Bi3+和Gd3+可能形成能量传递的桥梁,使能量在基质与激活剂离子之间高效传递。当15%mol Al3+和Bi3+以及25% molGd3+共同掺入到YBO3：Eu3+晶格中时,可以获得最强的发光强度和最佳的色纯度,样品的发光强度达到商用粉的1.15倍,显色性能亦优于商用红色荧光粉。其次,我们从提高(Y,Gd)BO3：Eu3+的色纯度考虑,制备了(Y0.65-xGd0.25Mx)BO3：0.10Eu3+(M=Li,Na,K,0.00≤x≤0.10)系列荧光材料,研究它们在真空紫外激发下的发光性能。随着Li+,Na+和K+的掺入,(Y,Gd)BO3：Eu3+中Eu3+周围的晶格环境对称性被破坏,对应于610nm和626nm处的红光发射强于对应于591nm处的橙光发射强度,从而色纯度显著改善。而且由于这些碱金属离子的核电荷数与Y3+相差较大,可能在导带和禁带之间形成了缺陷能级,提高了Eu3+的能量传递效率,发光效率提高。最佳配比样品的红橙比为1.10,发光强度达到商用粉的1.05倍。更多还原

【Abstract】 The study of properties of phosphors is essential to improve the performance of the high-definition color PDP. Nowadays, (Y,Gd)BO3:Eu3+ is recognized as one of the best commercial red phosphors for PDP due to its high VUV absorbency and extraordinarily high luminescent efficiency under VUV excitation. However, all of these advantages do not make (Y,Gd)BO3:Eu3+ as a desired VUV phosphors because of its luminescent efficiency and chromaticity problem. So the research on the improvement of existing phosphors or the development of new red phosphors is necessary. Experimental and theorital research is contained in this thesis:A) the improvement of orthoborate phosphor (Y,Gd)BO3:Eu3+ with the incorporation of several cations; the synthesization and optical properties of series new borate phosphors; B) the calculation of the electronic structure of YBO3 and the optimization of industrialization preparation technology.In order to improve the luminous intensity, Y0.75-xGdxAl0.10BO3:0.10Eu3+,0.05R3+ (R=Sc,Bi; 0.00≤x≤0.45) are synthesized by solid-state reaction. Their luminescent properties under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation are researched. The results indicate that with the incorporation of Al3+、Sc3+、Bi3+ and Gd3+, the higher intensity and better chromaticity are obtained because Gd3+ and Bi3+ played an inter-mediate "bridge" between the sensitizer and the activator (Eu3+) in energy transfer to produce light in (Y,Gd)BO3:Bi3+, Eu3+ system more effectively. The best chromaticity as well as the strongest luminescence can be obtained when 5%mol Al3+、5%mol Bi3+ and 25%mol Gd3+ are co-doped into the host lattice of YBO3:Eu3+, and the emission intensity came to its maximum which was nearly 115% compared to the red commercial phosphor (Y,Gd)BO3:Eu3+. On the other hand, (Y0.65-xGd0.25Mx) BO3:0.10Eu3+(M=Li, Na,K; 0.00≤x≤0.10) are synthesized by solid-state reaction. Their with the incorporation of Li+, Na+ or K+, the high symmetry around Eu3+ is destroyed and the ratio of red emission to orange one increased, leading to better chromaticity. (Y,Li)0.65Gd0.25BO3:0.10Eu3+ shows the best chromaticity and highest luminescent intensity which was nearly 105% compared to the red commercial phosphor (Y, Gd)BO3:Eu3+.更多还原