Nd^(3+)掺杂PbWO_4晶体的光谱特征和浓度效应  

Luminescence Spectra and Doping Effects in Nd^(3+)-doped PbWO_4 Single Crystals

作　　者：黄彦林[1] 赵连泽[2] 谢建军[3] 

机构地区：[1]苏州大学材料工程学院,江苏苏州215021 [2]南京大学地球科学系,江苏南京210093 [3]中国科学院上海硅酸盐研究所,上海200050

出　　处：《发光学报》2006年第6期891-896,共6页Chinese Journal of Luminescence

摘　　要：钨酸铅晶体(PbWO4)是新型的闪烁晶体,针对其广阔的光电子应用,实验测试了Nd3+掺杂PbWO4晶体的吸收光谱,讨论了不同的Nd3+掺杂浓度对于吸收系数和PbWO4光学吸收边的影响。依据Judd-Ofelt理论计算了吸收截面积、强度参数、量子荧光效率、荧光分支比等。讨论了不同浓度Nd3+掺杂的PbWO4晶体的光致发光光谱;室温LD808nm泵浦下,1.06μm荧光发射的荧光强度、荧光寿命和发射截面积,论述了这些性能随Nd3+掺杂浓度的变化关系。Four kinds of Nd^3 ＋ doped PbWO4 single crystals with different doping concentrations were grown by a vertical Bridgman method and Czochralski method. The purpose of this research is to investigate the influence of Nd^3＋ doping concentration on the band gap structures and the luminescence properties on the base of optical absorption edge and luminescence of PbWO4 single crystals, respectively. The optical absorption spectra of PWO： Nd^3＋ crystals were measured at first. The dependence of absorption coefficient and the optical absorption edges on the doping levels of Nd^3＋ ion were investigated. Compared to that of pure PbWO4, the optical absorption edges in Nd^3 ＋ doped samples at lower concentration 0. 15 % show the shift to high energy region （ short wavelength）. With increasing of Nd^3＋ doping, the optical absorption edge greatly shifts to the low energy region （long wavelength）. Based on the J-O theory, the phenomenological intensity parameters, intermanifold luminescence branching ratios, irradiative lifetime of the 4F3/2 level, the absorption and emission cross section of the PbWO4： Nd^3＋ crystals were calculated. Photoluminescence of PbWO4： Nd^3＋ crystals were discussed. In PbWO4： Nd^3＋ , luminescence from PbWO4 host, especially the exeiton excitation, are supressed with increasing of Nd^3＋ doping concentration ; and in Nd^3＋ heavily doped PbWO4, new excitation bands related to the oxygen vacancy were created. Fluorescence intensity and lifetime of ^4F3/2→^4I11/2 excited by laser diode （LD） and its lifetime at room temperature show a dependence of Nd^3＋ concentration. Under excitation by 808 nm laser diode, PbWO4： Nd^3＋ 2.0% show an efficient 1.06 μm emission （950 - 1 100 nm）.

关 键 词：钨酸铅单晶 Nd^3+掺杂 发光光谱 浓度效应 光学材料 

分 类 号：O482.31[理学—固体物理]