PEG对Ca_(0.68)Mg_(0.2)SiO_3:0.12Eu^(3+)红色荧光粉形貌及发光性能影响的研究

Effect of PEG on crystal structure and luminescent properties of Ca_(0.68)Mg_(0.2)SiO_3:0.12Eu^(3+) red phosphors

采用化学共沉淀法一次煅烧制备红色荧光粉Ca0.68Mg0.2SiO3∶0.12Eu3+的基质材料,借鉴表面扩散原理对红粉进行铕元素掺杂。用X射线衍射仪、荧光分光光度计和扫描电子显微镜对试样的晶体结构,发光性能及表面形貌进行了表征,进而研究了PEG的添加量对粉体形貌及发光性能的影响。结果表明:制得的基质粉末为CaSiO3,并含有少量的CaMg(SiO3)2,PEG的添加对样品结构有一定影响。与此同时可有效提高粉体的分散度和分布均匀性,改善粒子的形貌,荧光粉的发光强度随PEG的添加量增加出现了先增加后减小的趋势,这是因为PEG的量过多,影响了Eu3+及Mg2+取代Ca1、Ca2、Ca3格位,尽管晶体结构趋于完整,也不利于样品的发光。PEG的最佳添加量为样品质量的1%,此时粉体粒子直径约1.3~1.5μm,为类球状,PEG的添加大大提高了荧光粉的发光强度。

Ca0.6g Mg0.2 SiO3 ： 1. 2Eu^3＋ red phosphors were synthesized by one-step calcination process of precursor prepared by chemical precipitation. Then surface diffusion theory was applied to adulterate Eu into the red phosphor. The X-ray diffraction （XRD）, fluorescence spectrophotometry and scanning electron microscope （SEM） were employed to characterize the crystal structure,luminescent properties and surface morphology, respectively. The effects of adding of PEG on the characteristics of luminescence and surface morphology have also been investigated. It was found that the host powder was demonstrated to be CaSiO3 ,and contained a small amount of CaMg（SiO3 ）2. The adding of PEG changed the crystal structure,improved the dispersity and the particle morphology and decreased the granularity of the products. The luminous intensity of fluorescence was first increasing and then decreasing with increasing the amount of PEG. Because PEG was too much, Eu^3＋ and Mg^2＋ replacing the sites of Ca1 ,Ca2 ,Ca3 was influenced. Although the crystal structure become more complete,luminescence intensity of samples still decreased. The best adding amount was 1% of the total sample. Powder particle diameter was about 1.3～1.5μm and morphology was near-spherical. Furthermore,it enhanced luminescence intensity dramatically.