ZnO掺杂对Gd_2O_2S∶Tb晶体结构及发光性能的影响

Effect of Dopant ZnO on Crystal Structure and Luminescent Property of Gd_2O_2S∶Tb Phosphor

采用共沉淀法制备前驱体,通过固相反应制备了Gd2O2S∶Tb荧光粉。结果表明,采用氧化锌的掺杂,提高了荧光体的发光性能。选择合适的Zn2+浓度,可以通过控制焙烧条件,控制其粒径分布,使晶型趋于完整;通过对XRD和光谱的分析,可以清楚看出ZnO的添加,并未产生新相,而是使晶胞变小,使Gd3+与Tb3+以及Tb3+之间更容易发生能量传递,增强Tb3+离子的自敏化作用,加强5D4—7Fj发射,猝灭5D3—7Fj的发射,在提高发光亮度的同时,提高了荧光粉的色纯度。

The phosphor raw materials were preliminarily dissolved in a mineral acid and added oxalic acid to co-precipitate oxalates of rare earth elements, and calcined to obtain mixed oxides, then added various flux and zinc oxide, followed by firing at a proper firing condition. The brightness of terbium-activated gadolinium oxysulfide phosphors can be enhanced and size distribution also be controlled by doping the phosphor with a proper amount of zinc oxide. By the analysis of X-ray diffraction and the excitation spectra andemission spectra, it can be confirmed that no new phase is introduced and lattice size is diminished. In this way, it may easily occurred energy transmission between Gd^3＋ ion and Tb^3＋ ion as well as Tb^3＋ ion and Tb^3＋ ion. Therefore, self-sensitization of Tb^3＋ ion can be enhanced, ^5D4-^7Fj transition is further improved and ^5D3-^7Fj transition is lowered. The enhancement of luminescent properties including brightness and chroma purity are also confirmed due to incorporation of Zn^2＋ ion.