高耐熱性を有する白色ＬＥＤ用新規蛍光体の開発

研究了(Ba，Sr)_3SiO_5：Eu~(2+)的抗湿性和热猝灭的原子尺度来源。用粉末X射线衍射法和光致发光(PL)法对湿气诱导降解进行了表征。用Rietveld精化和密度泛函理论(DFT)计算分析了晶体结构和电子分布。结果表明，电子的色散与有效碰撞有关，进而与主晶格的稳定性有关。此外，还提出了Voronoi-Dirichilet多面体(VDP)来评价周围离子对电子色散的空间影响。最后，我们将全局不稳定指数(GII)与晶格振动引起的热猝灭联系起来，表明热力学对荧光粉的意义。II.报道了一种新的ABC4(O，N)7型氧氮化物荧光粉SrLuAl2Si2O2N5。荧光粉的合成采用传统的固相法。晶体结构经X-射线衍射法确证。用光致发光光谱研究了Ce3+和Eu2+掺杂的发光性质。用热重-差热分析(TG-DTA)和氧/氮分析对其热降解性能进行了分析。通过量子效率和热猝灭实验对荧光粉的性能进行了表征。

I.Atomic scale origin of moisture resistance and thermal quenching for (Ba,Sr)3SiO5:Eu2+ was investigated. The moisture induced degradation was evaluated by the powder X-ray diffraction and photoluminescence (PL) emission. The crystal structure and electron distribution was analyzed by Rietveld refinement and density functional theory (DFT) calculation. It is found that the dispersion of electrons is relevant to effective collision and then the stability of the host lattice. Furthermore, Voronoi-Dirichilet polyhedron (VDP) is put forward to evaluate the spacial influence on the dispersion of electrons by the surrounding ions. Finally, we correlated global instability index (GII) to the lattice vibration induced thermal quenching, suggesting the significance of thermodynamic for phosphor hosts.II.A new ABC4(O,N)7-type oxynitride phosphor SrLuAl2Si2O2N5 is reported. The phosphors were synthesized by conventional solid state method. The crystal structure was confirmed by X-ray diffraction. The luminescence properties doping Ce3+ and Eu2+ were investigated by photoluminescence spectra. The thermal degradation was analyzed by thermogravimetric different thermal analysis (TG-DTA) and oxygen/nitrogen analysis. The performance of the phosphors was characterized by quantum efficiency and thermal quenching tests.