Colloidal processing of Gd2O3:Eu3+ red phosphor monospheres of tunable sizes: Solvent effects on precipitation kinetics and photoluminescence properties of the oxides
Colloidal processing of Gd2O3:Eu3+ red phosphor monospheres of tunable sizes: Solvent effects on precipitation kinetics and photoluminescence properties of the oxides
复制标题
DOI：
10.1016/j.actamat.2011.03.004
复制
发表时间：
2011-05-01
期刊：
影响因子：
9.4
通讯作者：
Sakka, Yoshio
中科院分区：
文献类型：
--
作者：
Li, Ji-Guang;Zhu, Qi;Sakka, Yoshio
针对Gd/Eu二元体系，尝试了尿素均相沉淀法合成碱性碳酸盐微球，重点研究了粒度和阳离子分布的控制。结果表明，使用水/有机溶剂混合物作为反应介质，不仅可以方便地将粒度控制在50-500 nm的宽范围内，而且还有效地缓解了Gd和Eu组分之间的有害顺序沉淀。从碳酸盐沉淀机理、有机共溶剂的介电常数和表面张力等方面对实验结果进行了讨论。碱性碳酸盐单晶石在800℃下热处理12h，得到了分散良好的(Gd1-xEux)(2)O-3荧光粉，在259 nm电荷转移激发下，在610 nm处显示出锐利的红色发射。该荧光球对Eu3+的发光猝灭浓度为7-9at.%，且具有明显的尺寸依赖发光行为。610 nm发射的强度和发光的不对称因子[I(D-5(0)->；F-7(2))/i(D-5(0)->；F-7(1))]都随着颗粒尺寸的减小而稳步增加，这分别归因于晶界密度的降低和表面/体积效应的增强。本工作合成的(Gd1-xEux)(2)O-3荧光球具有良好的形态均匀性和紧密堆积能力，在各种照明和显示器件中具有潜在的应用前景。(C)2011 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The synthesis of basic carbonate monospheres was attempted for the Gd/Eu binary system via urea-based homogeneous precipitation, with emphases on particle size and cation distribution control. It was demonstrated that the use of water/organic-solvent mixture as the reaction medium not only allows facile particle size control in the wide range of similar to 50-500 nm but also effectively alleviates the detrimental sequential precipitation between the Gd and Eu components. The results are discussed from the mechanism of carbonate precipitation and the dielectric constant and surface tension of the organic co-solvent. Annealing the basic carbonate monosheres at 800 degrees C for 12 h yields well-dispersed (Gd1-xEux)(2)O-3 phosphor particles that exhibit sharp red emissions at 610 nm under 259 nm charge transfer excitation. The phosphor spheres show a luminescence quenching concentration of 7-9 at.% for Eu3+ and clearly size-dependent luminescent behavior. Both the intensity of the 610 nm emission and the asymmetry factor of luminescence [I(D-5(0) -> F-7(2))/I(D-5(0) -> F-7(1))] steadily increase with smaller particle-size findings that have been ascribed to decreased grain-boundary density and enhanced surface/volume effects, respectively. With their excellent morphological uniformity and close-packing ability, the (Gd1-xEux)(2)O-3 phosphor spheres synthesized in this work may find potential applications in various lighting and display devices. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.