【作者】 潘政薇；

【导师】 傅仁利；

【作者基本信息】 南京航空航天大学 ， 材料学， 2010， 硕士

【摘要】 采用高温固相反应法（SSR）和Pechini-溶胶凝胶法两种工艺制备了稀土离子掺杂的正硅酸盐荧光粉。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、荧光分光光度计对样品进行了分析,研究了碱金属离子掺杂、稀土离子掺杂、合成工艺对荧光粉物相组成、微观结构、发光性能的影响。研究结果表明:（1）Pechini-溶胶凝胶法与高温固相反应法相比,制得的荧光粉物相更加纯净;粉体颗粒粒径更加均一,且呈球形形态,有利于涂覆。（2）Ba²⁺掺杂的Sr₂SiO₄:Eu²⁺中Eu²⁺离子分布于两个不同的基体晶格位置,使发射光谱分别产生了绿光和黄光波段的发射;改变Ba²⁺、Eu²⁺离子掺杂浓度可以对荧光粉进行有效的光谱剪裁。碱金属离子Ba²⁺的掺杂使Ba_xSr_2-x-ySiO₄:Euy2+荧光粉的α′-Sr₂SiO₄物相结构得到了稳定。碱土金属离子Ca²⁺、Ba²⁺掺杂的Li₂SrSiO₄:Eu²⁺荧光粉具有宽带的激发和发射光谱,在色度图上分别位于蓝光区和黄光区。（3）阐述了稀土离子Eu²⁺、Ce3+共掺杂的Li₂SrSiO₄荧光粉中其存在的能量传递现象,同时通过理论公式的计算和证明确定了能量传递的机制;稀土离子Eu²⁺、Ce3+共掺杂的Li₂SrSiO₄荧光粉中存在电子偶极-偶极相互作用的Ce→Eu能量迁移现象;Li₂SrSiO₄:Ce, Eu在蓝光和黄光区域有两个发射峰,分别位于400 nm和570 nm处。当Ce3+离子浓度为0.005,Eu²⁺离子浓度n≥0.75时,产生浓度猝灭现象。更多还原

【Abstract】 Rare-earth doped silicates phosphors were prepared by high temperature solid state reaction （SSR） and Pechini-sol-gel route, respectively. Using X-ray Diffractometer （XRD）, Scanning Electron Microscope （SEM） and fluorescent spectrophotometer, the influences of different doping ions including alkaline-earth metal ions and rare-earth ions, and preparing methods on phase compositions, microstructures and optical properties of silicates phosphors were studied. Experimental result show: （ⅰ） Comparing with SSR, Pechini-sol-gel route synthesized pure single phase phosphors with uniform phosphor particles and beneficial spherical shape. （ⅱ） Ba²⁺-doped Sr₂SiO₄:Eu²⁺ phosphors (Ba_xSr_2-x-ySiO₄:Euy2+) show two intense emission bands at green and yellow regions of spectrum, originated from Eu²⁺ ions accommodated at two different sites in the host crystal, whose peaks depend on the concentrations of Ba²⁺ and Eu²⁺ ions. Additional, Ba²⁺-doping favored the stabilization ofα′-Sr₂SiO₄ phase. Intense and broad excitation spectra and emission spectra were obtained by doping Ca²⁺ or Ba²⁺ ions in Li₂SrSiO₄:Eu²⁺ phosphor, which show blue emitting and yellow emitting in chromaticity diagram, respectively. （ⅲ） The energy transfer from Ce3+ to Eu²⁺ （Ce→Eu） was demonstrated to be the type of electric dipole-dipole interaction in the Eu²⁺ and Ce3+ codoped Li₂SrSiO₄ phosphor. There were broad blue and yellow emissions peaked at 400 nm and 570 nm, respectively. It was observed that Li₂SrSiO₄:0.5%Ce3+,0.75%Eu²⁺ displayed the highest emission intensity, and higher concentration of Eu²⁺ resulted in concentration quenching.更多还原