Synthesis, size control and luminescence properties of monodispersed(Y,Gd)2O3:Eu3+ phosphor microspheres

通过均匀沉淀成功实现了 Ln(OH)CO3·nH2O (Ln=Y,Gd,Eu) 单分散微球的合成和尺寸控制。定义了单球体的形成域。研究发现，有机共溶剂的添加促进了稀土阳离子成分的共沉淀。通过碱性碳酸盐前驱体的煅烧得到分散的(Y,Gd)2O3:Eu3荧光粉微球。经证实，荧光粉单球在减小粒径时表现出更强的Eu3发光。利用从Gd3到Eu3的能量转移，发光强度得到增强。由于Gd3的电负性低于Y3，荧光粉在较高的Gd3含量下表现出电荷转移激发带中心的红移。无论 Gd3 含量如何，荧光粉的荧光寿命测定为约 1.5 ms。

Synthesis and size control of monodisppered microspheres of Ln(OH)CO3・nH2O (Ln=Y,Gd,Eu) have been successfully achieved via homogeneous precipitation. Formation domain of the monospheres was defined. It was found that the addition of organic co-solvent promotes coprecipitation of the constituent rare-earth cations. Dispersed (Y,Gd)2O3:Eu3+ phosphor microspheres were obtained by calcining the basic carbonate precursors. It was confirmed that the phosphor monospheres exhibit stronger luminescence of Eu3+ at a decreased particle size. Utilizing the energy transfer from Gd3+ to Eu3+, the luminescence intensity was enhanced. Owing to the lower electronegativity of Gd3+ than Y3+, the phosphors exhibit red-shifted center of the charge transfer excitation band at a higher Gd3+ content. The fluorescence lifetime was determined to be about 1.5 ms for the phosphors, irrespective of the Gd3+ content.