Dy^(3+)掺杂CaTiO_3:Pr^(3+)的合成与光谱特征

Synthesis and spectroscopic properties of CaTiO_3: Pr^(3+) doped with Dy^(3+) ions

以Ti(OC4H9)4,Ca(NO3)2.4H2O,氧化物Pr2O3和Dy2O3等为原料,采用溶胶-凝胶法合成了具有立方晶系晶体结构,空间群为Pm3m的Dy3+掺杂CaTiO3:Pr3+红色长余辉发光材料。采用XRD,SEM,荧光分光光度计等对其物相组成、微观结构和发光性质等进行了测试分析研究。结果表明,Dy3+的掺入有利于提高CaTiO3:Pr3+的发光亮度和延长其余辉时间,Dy3+使CaTiO3:Pr3+的激发光谱在450~520 nm之间的3个小激发峰增强。探讨了Dy3+可使CaTiO3:Pr3+发光效果增强的原理,Dy3+在CaTiO3:Pr3+晶格中形成了更为合适的电子陷阱有利于提高其余辉性能。

Red long-lasting phosphorescence materials of CaTiO3 co-doped with Pr^3＋ and Dy^3＋ ions were obtained by the sol-gel method using stoichiometric amounts of [Ti（OC4H9）4], [-Ca（NO3）2 · 4H2O], [Pr2O3] and [Dy2O3] as reagents. Ethylene Glycol [HOCH2CH2OH] was selected as solvent. The samples of calcium titanate precursor gel were heated at temperature from 850℃ to 950℃ in air to form CaTiO3： Pr^3＋, Dy^3＋. The composition, microstructure and spectroscopic properties of the samples were characterized by X-ray diffraction （XED）, scanning electron microscope （SEM） and fluorospectrophotometer. The patterns of X-ray diffraction confirm the presence of cubic CaTiO3 with a space group Pm3m. At room temperature, the samples exhibit intense red emission at 618 nm after being excited in UV or sunlight. The intensity of this emission was enhanced with Dy^3＋-doped. After the glow time the increasing of CaTiO3 ： Pr^3＋ phosphor could be explained by Dy3＋ hosts of the materials. The 3 excitation peaks from 450 nm to 520 nm were increased by Dy^3＋ in the CaTiO3 ： Pra＋ excitation spectrum. The internal defects are presented as a result of substitution of Ca^2＋ by Pr^3＋ , and Dy^3＋ ions enhance emission intensity and increase the decay time of CaTiO3： Pr^3＋.