白光LED用LaPO4:Eu3+红色荧光粉的合成与表征

利用水热法制备了性能稳定的红色荧光粉LaPO4:Eu3+,同时研究了不同的Eu3+浓度、煅烧温度对荧光粉发光性能的影响.通过X射线粉末衍射(XRD)和扫描电子显微镜(SEM)来表征荧光粉的晶体结构和颗粒大小及形貌;用激发光谱和发射光谱以及荧光衰减曲线来表征荧光粉的荧光性能.结果表明:未煅烧时前躯体主要是六方晶相LaPO4·0.5H2O,煅烧温度在900℃时,所制备样品为单斜相LaPO4:Eu3+;SEM图像显示5 at.%Eu3+掺杂LaPO4呈椭球形,颗粒长约为500 nm,宽约为300 nm.最大发射波长和激发波长分别为592 nm和393 nm,发射光谱中592 nm和612 nm的发射峰对应的是Eu3+离子的5D0→7F1和5D0→7F2跃迁.其荧光寿命为3.32 ms.

Synthesis and characterization of LaPO4:Eu3+ red phosphor for in white LED application

A stable LaPO4:Eu3+ red phosphor was prepared by hydrothermal method.The influences of the concentration of Eu3+ and calcination temperature on the luminescent properties were studied.The crystal structure,particle size and morphology were characterized by X-Ray Powder Diffraction(XRD) and Scanning Electron Microscope(SEM) techniques.The luminescent properties of phosphor were measured by emission spectra,excitation spectra and decay curve.The results indicate that the precursors are the LaPO4·0.5H2O crystals of hexagonal without heat-treatment,the as-prepared samples are LaPO4:Eu3+ crystals of monoclinic phase annealing at 900 ℃,the length of crystal is about 500 nm,the width is about 300 nm.The maximum emission and excitation wavelength are at 592 nm and 393 nm,respectively.The emission peaks at 592 nm and 612 nm are corresponding to 5D0→7F1 and 5D0→7F2 transition of Eu3+ ions in emission spectrum.The fluorescence lifetime of LaPO4:Eu3+ phosphor is 3.32 ms.