蓝色荧光粉Sr2B5O9Cl:Eu2+发光特性的研究

采用高温固相法合成了近紫外光激发的蓝色荧光粉Sr₂B₅O₉Cl:Eu²⁺,研究了SrCl₂ ·6H₂O用量和Eu²⁺浓度对其结构和发光性能的影响.随着Eu²⁺浓度的增加,其结构无明显变化,发光强度先增强后减弱,当其浓度为8mol%时,荧光粉的发光强度最大;当用Ca取代Sr时,荧光粉的发射峰从425 nm红移到453 nm. 适当过量 关键词： 氯硼酸盐 蓝色荧光粉 LED

Luminescence characteristics of Sr2 B5O9 Cl:Eu2+ phosphors for white LED

A series of blue-emitting phosphors M₂B₅O₉Cl: Eu²⁺(M=Ca, Sr) were synthesized by solid-state methods. And the phosphors were characterized by XRD and photoluminescence emission (PL) and excitation (PLE) spectra. The factors that affect the PL intensity of phosphor Sr₂B₅O₉Cl have been investigated, and the optimal conditions to obtain the blue emitting phosphor are 8 mol% Eu²⁺concentration, 5.0mol % excess of SrCl₂. As Ca partially or completely substituted Sr in the host Sr₂B₅O₉Cl, the emission peak shifts from 425 to 453 nm. The most important is that the phosphors M₂B₅O₉Cl: Eu²⁺(M=Ca, Sr) show strong absorption in the region of 350—400 nm, which matches well with the emission of the near-ultraviolet or purple LED chips. Comparison with the commercial blue-emitting phosphor, the PL intensity of phosphor Sr_1.92Eu_0.08B₅O₉Cl is about 1.8 times that of the commercial blue emitting phosphor BAM. Thus, the phosphors M₂B₅O₉Cl: Eu²⁺ (M=Ca, Sr) show great potential as the candidate for blue phosphor in n-UV or purple based white LEDs.