(La,Ce,Tb)BO_3的合成及光谱性质

Synthesis and Luminescence Properties of (La,Ce,Tb)BO_3 Phosphors

采用高温固相法合成了(La,Ce,Tb)BO3绿色发光粉,并对该发光粉进行了XRD和SEM分析。结果表明:(La,Ce,Tb)BO3的晶体结构和LaBO3相同,Ce3+、Tb3+的掺入并没有改变晶体的结构,发光粉颗粒大小均匀,形貌规则,粒度在5μm左右。研究了(La,Ce,Tb)BO3的光谱性质,在(La,Ce,Tb)BO3的发射和激发光谱中除了有Tb3+的特征发射和激发峰外,还有Ce3+的特征发射和激发峰。比较了(La,Ce)BO3发射光谱和(La,Tb)BO3的激发光谱,两者存在重叠,这为Ce3+→Tb3+的能量传递提供了条件。将(La,Ce,Tb)BO3的发射光谱与商品粉(La,Ce,Tb)PO4进行比较,两者的发射主峰都在541nm处,(La,Ce,Tb)BO3在489nm处的峰位稍有红移,通过计算表明,(La,Ce,Tb)BO3的发光亮度达到商品粉(La,Ce,Tb)PO4的94.7%。因此,(La,Ce,Tb)BO3是一种很有应用前景的绿色发光粉。

The phosphor of diffraction （XRD） patterns crystal structure was not e （La,Ce,Tb） BO3 was synthesized by high temperature solid state reaction. X-ray indicated that （La, Ce, rib）BO3 and LaBO3 have the same crystal structure, the hanged by doping with Ce^3＋ and Tb^3 ＋. Emission scanning electron microscopy （SEM） image showed that the phosphor particles is uniform, the morphology is regular, and the granularity is about 5 μm. The luminescence properties of （La, Ce,Tb）BO3 phosphor were studied, both the Tb^3＋ characteristic emission and excitation peaks and the Ce^3＋ characteristic emission and excitation peaks were observed in the emission and excitation spectrum of （La, Ce, Tb）BO3. The emission spectra of Ce^3＋ in （La, Ce）BO3 and the excitation spectra of Tb^3 ＋ in （ La, Tb） BO3 have large superposition at 330 - 400 nm regions, which supply good conditions for energy transfer from Ce^3＋ to Tb^3＋. The energy transfer between Ce^3＋ and Tb^3＋ is primarily as resonance transfer. Both of （La, Ce, Tb）BO3 phosphor and commercial phosphor （La, Ce, Tb）- PO4 have main emission peak at 541 nm. Comparing （ La, Ce, rib） BO3 phosphor with commercial phosphor （ La, Ce, Tb） BO3, （ La, Ce, Tb） BO3 phosphor has a little red shift at 489 nm and its relative emission intensity was 94.7% of the commercial phosphor （ La, Ce,Tb） PO4. Therefore, it is expected that （ La, Ce,Tb） BO3 phosphor would be a promising green-emitting phosphors.