【摘要】 采用高温固相法合成了Li+、Na+、K+和Si4+作为电荷补偿剂的Ca2.96Eu0.04(PO4)2白光LED用红色荧光粉。采用X射线衍射仪、荧光光谱仪对材料的物相和发光性能进行了表征。样品的激发光谱由200~310 nm的电荷迁移带和310~500 nm的锐线光谱组成,其中396 nm的激发强度最大。发射光谱主要由5D0→7F1(593 nm)和5D0→7F2(616 nm)跃迁导致的发射峰构成。掺入Li+、Na+、K+和Si4+可以有效提高Ca2.96Eu0.04(PO4)2荧光粉的发光强度,同时对荧光粉的寿命和色坐标影响不大。荧光粉的色坐标均位于红色区域。更多还原

【Abstract】 Novel Li+-,Na+-,K+-,and Si4 +-doped Ca2. 96Eu0. 04( PO4)2red phosphors were synthesized using a conventional solid-state reaction route. The effects of codoping of charge compensatory ions on the phase and luminescent properties of Ca2. 96Eu0. 04( PO4)2red phosphors were investigated by X-ray diffraction and photoluminescence spectra. The excitation spectra include both broad band( 200- 310 nm) and sharp peaks( 310- 500 nm). From emission spectra,it is observed that these phosphors exhibit two dominating bands situated at 593 and 616 nm,originating from the5D0→7F1and5D0→7F2transition of the Eu3 +ion,respectively. The luminescence of Ca2. 96Eu0. 04-( PO4)2can be enhanced by the incorporation of Li+,Na+,K+,and Si4 +. Furthermore,the charge compensation mechanism was discussed. The charge compensatory additives have little influence on the decay times and CIE of all the phosphors. The CIE chromaticity coordinates of these phosphors all locate in the red region. It implies that Ca2. 96Eu0. 04( PO4)2is a good candidate as a red-emitting phosphor pumped by near-ultraviolet( NUV) InGaN chip for fabricating white lightemitting diodes( wLEDs).更多还原