Sr_2MgSi_2O_7：Tb^(3＋),Li~＋荧光粉的合成和发光机理

Synthesis and Luminescent Mechanism of Sr_2MgSi_2O_7:Tb^(3+),Li^+ Phosphor

采用高温固相法合成Sr2-mMg1-nSi2O7∶mTb3+,nLi+(m=0.03~0.50,n=m)系列荧光粉。使用X射线衍射仪和荧光光谱仪对样品的物相和发光性质进行了表征。在377 nm紫外光激发下,荧光粉的发射光谱呈多谱带发射,主峰位于490 nm,542 nm,590 nm和613 nm处,分别对应于Tb3+的5D4→7FJ(J=6,5,4,3)跃迁发射。调节Tb3+离子掺杂浓度,可实现荧光粉的发光颜色从蓝到白、黄、绿的可调发射;名义组成为Sr1.95Mg0.95Si2O7∶0.05Tb3+,0.05Li+的荧光粉在紫外光(377 nm)激发下发白光,其色坐标(0.322,0.317)接近纯白光(0.33,0.33),是一种潜在的LED用单基质白光荧光粉。

The phosphors designed as Sr2-mMg1-nSi2O7∶mTb3＋,nLi＋（m=0.03~0.50,n=m） were prepared by the high temperature solid state reaction.Crystallization and optical properties were investigated by using powder X-ray diffraction and fluorescence spectrophotometer,respectively.Under the excitation of ultraviolet（377 nm）,the emission spectra of these phosphors exhibit sharp multi-emission lines peaked at about 490 nm,542 nm,590 nm and 613 nm corresponding to the 5D4→7FJ（J=6,5,4,3） typical transitions of Tb3＋,respectively.The luminescence color can be tuned from blue to white,yellow and green by adjusting the doping concentration of Tb3＋ ions.It had been found that the nominal composition Sr1.95Mg0.95Si2O7∶0.05Tb3＋,0.05Li＋ phosphor provides a white emission（0.322,0.317） that is very close to the standard white（x=0.33,y=0.33）,which shows that it is a potential single-phased white phosphor for LED-based UV-chip.