Eu3+激活硼酸盐基质新型红色荧光粉的制备及发光性能

采用传统高温固相反应法制备了一种新的白光LED用红色荧光粉LiLa2 O2 BO3:Eu3+,并对其晶体结构及发光性能进行了系统研究.XRD分析证实Lila2BO3晶体能够稳定存在,并利用Le Bail模型计算得到其晶胞参数.荧光光谱证实:Eu3+离子在LiLa2O2BO3晶体中占据非反演对称中心格位,该系列荧光粉在紫...

Synthesis and Luminescent Properties of Eu3+-activated Novel Borate-based Red-emitting Phosphors for White LED

A series of novel red phosphors LiLa₂O₂BO₃ ∶ Eu³⁺ were synthesized by conventional solid state reaction method using H₃BO₃ (99.5%), La₂O₃ (99.99%), Eu₂O₃ (99.99%) and Li₂CO₃ (97.0%) with different Eu³⁺ concentrations. The crystal structure and spectral features of the phosphors were characterized by XRD,excitation and emission spectra, respectively. The XRD pattern result indicates that the LiLa₂O₂BO₃ crystals are stably existed.The lattice parameters were calculated by the Le Bail model method. We can also conclude from XRD patterns that unknown phases are formed with higher concentration Eu³⁺ doping. The excitation spectrum data demonstrate that these phosphors could be effectively excited by ultraviolet (UV) (396 nm) and blue (466 nm) light, which represent highly future prospects in both ultraviolet and blue light emitting diodes (LED) chips. Due to the ⁵D₀→⁷F₂ transition of Eu³⁺, the phosphors have best emission spectrum performance of 613 nm and 623 nm, illustrating Eu³⁺ occupy the non-centrosymmetric lattice site in LiLa₂O₂BO₃ phases. The optimal doping concentration of Eu³⁺ was 20%. Our further research indicates the luminescent intensity increases significantly by doping optimal concentration of Si⁴⁺ ions. The CIE chromaticity coordinates are much closer to the standard of NTSC(x=0.670,y=0.330) by partly replacement of B³⁺ by Si⁴⁺ ions.