碱金属和三价Eu离子共掺杂的碱土钼酸盐荧光粉发光性能

采用固相法制备了用于白光LED的Eu3+和碱土离子(Li+,Na+,K+)共激活的钼酸盐荧光粉AMoO4(A=Ca,Sr).通过X射线衍射图片看出,Eu3+和Na+的掺入降低了晶格参数,同时衍射峰强度明显增加.本文研究了荧光粉的激发光谱和发射光谱.它的激发谱覆盖了从240nm到500nm的范围,在470nm处有一个激发峰,这说明它能够被GaN LED发出的蓝光有效激发.发射谱表明它能够发射峰值位于616nm和624nm的红光.实验研究了碱土离子的量(摩尔分数)对AMoO4:Eu3+发光性能的影响,0.25是最合适的掺杂量.反应时间和反应温度对发光性能也有很大的影响.搅拌均匀的反应物在800℃灼烧3h得到的样品发光强度最强.

Luminescent Properties of Alkali Metal Ion and Trivalent Europium Ion Co-activated Alkaline Earth Molybdate Phosphors

A series of trivalent europium ions(Eu3+) and alkali metal ions(Li+,Na+,K+) coactivated molybdate phosphor AMoO4 (A=Ca,Sr) was fabricated by solid-state reaction, which could be used as supplementary lighting material for white light emitting diodes (LEDs). X-ray diffraction (XRD) patterns show that the lattice parameters decrease and the diffraction intensity remarkably increase when Eu3+ and Na+ ions are doped into the phosphor. The excitation and emission spectra of samples are investigated. The excitation spectra cover the region from 240nm to 500nm and have an excitation peak at 470nm, which indicate that this phosphor can be excited effectively by the emission of GaN-based LED; the emission spectra show the samples can emit red light whose peaks are located at 616nm and 624nm. The influence of alkali metal ions dosage ( molar fraction) on the luminescent properties of AMoO4: Eu3+ is investigated and the results indicate that 0.25 is the appropriated dosage. The reactive time and temperature have obvious effect on the luminescent properties. The luminescent intensity will reach the maximum when it was sintered at 800℃ for 3h.