(Y,G d)BO_3∶Tb^(3+)的真空紫外及紫外激发光谱特性

Excitation Spectroscopic Properties of (Y,Gd)BO_3∶Tb in VUV and UV Range

采用传统的高温固相反应法合成出(Y,Gd)BO3∶Tb荧光体,对所制得的荧光体进行了晶体结构分析,分析结果表明结晶良好。(Y,Gd)BO3∶Tb在147 nm真空紫外光激发下的发射主峰在544 nm(Tb3+的5D4→7F5跃迁),是一种绿色发光材料。样品的真空紫外激发光谱及紫外激发光谱表明,(Y,Gd)BO3∶Tb的基质吸收带位于150 nm附近。Gd3+离子对真空紫外区的光吸收有增强作用,存在着Gd3+→Tb3+的能量传递。测量了荧光粉在室温下的荧光衰减特性,其余辉时间约为8 m s,能够满足显示显像技术的要求。因此,(Y,Gd)-BO3∶Tb是一种有前景的PDP用绿色发光材料。

The plasma display panel （PDP） was regarded as the most promising medium for the wall hanging high definition television （HDTV） because the large sized PDP could be made relatively easily. Moreover, it offers a fast response, a wide viewing angle, a lower energy consumption and other advantages. In PDPs, three primary color phosphors are excited by the vacuum ultraviolet radiation from inert gas plasma, which imposed a unique requirement on the phosphors. Green emitting phosphors was very important for plasma display panel because human eyes were sensitive to green color. ZnSiO4： Mn^2＋ which was used in plasma display panel as a green emitter has a long decay time, has a decay time longer than 10 ms. Long decay time was not beneficial to display. Searching for new emitting phosphors with short decay time excited by VUV photon was a urgent thing. （ Y, Gd ） BO3 ： Tb powders were prepared by the conventional solid reaction method. The structure of the powders was checked by XRD. The emission spectrum of （Y,Gd）BO3： Tb excited by 147 nm dominated by 544 nm emission ascribed to ^5D4→^7F5 transition of Tb^3＋ ions. VUV and UV excitation spectra of （Y,Gd） BO3： Tb were investigated. It was found that the host absorption was located at about 150 nm. The band centered at 150 nm of （Y, Gd）BO3： Tb is stronger than that of YBO3： Tb which indicated that Gd^3＋ enhanced the host absorption. New peaks were present at about 276 nm in the excitation spectrum of （ Y, Gd）BO3： Tb and were assigned to the ^8S7/2→^6IJ transitions of the Gd^3＋,this result indicates that there is an energy transfer between Gd^3＋ ions and Tb^3＋ ions. The fluorescence decay curve of （ Y, Gd） BO3 ： Tb indicated that the lifetime of green luminescence （at 10% intensity） of （Y, Gd）BO3： Tb is about 8 ms. The afterglow time of （ Y, Gd） BO3： Tb can meet the demand for display application.