稀土Gd^(3+)掺杂对Pb WO_4发光的增强  

Rare Earth Gd^(3+) Doping Improving Luminescence of Pb WO_4 Microcrystal

作　　者：周东方[1] 施朝淑[1] 张庆礼[2] 陈永虎[1] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,安徽合肥230029 [2]中国科学技术大学物理系,安徽合肥230026

出　　处：《发光学报》2001年第3期248-252,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目 ( 5 9732 0 40和 197740 5 3)

摘　　要：本文研究了稀土Gd3+ 掺杂于PbWO4 的发射光谱、激发光谱及其浓度依赖。Gd3+ 在PWO4 中的发光完全被猝灭 ,而PWO4 的发射光谱形状不变。掺入约 5 0ppm后PWO4 的绿光带有所增强 ,掺入约 10 0ppm后PWO4 的蓝光带有所增强。Gd3 + 的激发态进入PWO4 的导带并把能量反向传递给PWO4 基质是其可能的发光增强机制。低掺杂的PWO4The luminescence properties of PbWO 4 doped with Gd 3+ have been studied. The PbWO 4∶Gd 3+ microcrystal powder was obtained by solid phase reaction method. The microcrystal with strong green emission band was prepared in air with rich oxygen at 875℃ for 10 hours, and the microcrystal with strong blue emission band was prepared in vacuum with active carbon at 800℃ for 8 hours. By measuring the emission of PbWO 4∶Gd 3+ for 311nm excited by 274nm, and measuring the excitation spectrum of PbWO 4∶Gd 3+ from 200～300nm of 311nm emission, it can be concluded that the luminescence of Gd 3+ in PWO was quenched. So both the excited states 6I 7/2 and 6P 7/2 of Gd 3+ are located in the conduction band of PWO. The luminescence from 4f 4f transition of Gd 3+ is slow, its quenching should not increase the slow components of luminescence of PWO in general, so the luminescence of PWO∶Gd is still that of PbWO 4 host dominated by fast components. As a structure sensitive material, PWO is sensitive to oxygen during preparing and annealing. The strong green component of luminescence from PWO∶Gd powder compounded in air with rich oxygen is as about 100 times as that of crystal compounded in a atmosphere lack of oxygen, similar to that of crystal sample annealed in air. Its emission and excitation spectra are showed in Fig.1, and the concentration dependence of the peak emission intensity of PWO∶Gd is showed in Fig.2. For PWO∶Gd prepared in air, the intensity of the green emission of PWO is increased by doping with 50～100ppm Gd. But beyond 100 ppm, Gd doping will quench the luminescence of PWO. For PWO∶Gd powder prepared in vacuum with active carbon, its emission is mainly in blue band and the blue emission intensity is increased remarkably as 3～4 times as that from PWO crystal grown by Bridgman method. As shown in Fig.3 , the main wide excitation band peaked at 378nm is very different from that prepared and annealed by ot

关 键 词：PBWO4 晶体 GD掺杂 闪烁体材料 发光特性 增强 PWO4:Gd 稀土离子 

分 类 号：O734.3[理学—晶体学] TN104.3[电子电信—物理电子学]