Er/Yb共掺体系的光致荧光行为及相关物理过程研究  

Photoluminescence and its physical mechanism of Er/Yb co-doped borate-silicate glass

作　　者：彭扬[1] 李善锋[1] 张庆瑜[1] 李毅刚[2] 徐雷[2] 

机构地区：[1]大连理工大学三束材料改性国家重点实验室,大连116024 [2]复旦大学光科学与工程系,先进光子学材料与器件国家重点实验室,上海200433

出　　处：《物理学报》2007年第12期7286-7294,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50240420656)资助的课题.~~

摘　　要：采用固相反应方法,制备了Er2O3浓度固定为0.5mol%,Yb2O3浓度范围为0.0mol%—5.5mol%的Er/Yb共掺激光玻璃.通过吸收光谱、光致荧光光谱和上转换荧光光谱,研究了Yb2O3浓度对Er3+荧光特性的影响,并探讨了相关的物理机制.研究结果表明:Yb3+共掺对Er3+的4I13/2吸收截面的影响存在一个临界浓度.当Yb3+浓度超过此临界浓度时,吸收截面面积随Yb2O3浓度的增加而线性增加,从而导致Er3+的4I13/2→4I15/2辐射跃迁过程的增强.Yb3+掺杂显著提高了Er3+的荧光强度,并导致荧光光谱的明显宽化.定量分析表明,受主到施主的反向能量传递随Yb2O3浓度的增加而逐渐增加,但不是导致Er3+的4I13/2→4I15/2跃迁过程中荧光强度饱和的主要原因.而Yb3+掺杂所引起的荧光量子效率降低和抽运过程中存在的激发态粒子数本征饱和才是荧光强度饱和甚至降低的根本原因.Yb3+共掺杂引起的敏化作用而导致的Yb3+的2F5/2能级和Er3+的4I11/2能级粒子数密度增加,促进了Yb3+,Er3+之间合作上转换的增强.这是上转换荧光增强的主要贡献.Er/Yb co-doped borate-silicate glass with 0.5mol% Er2O3 were fabricated by solid reaction. The concentration of Yb2O3 was in the range of 0. 0mol% to 5.5mol% . The spectra of absorption, photoluminescence （PL） and up-conversion luminescence were analyzed. A critical value is found in the dependence of PL and absorption on the concentration of Yb2O3 . When the concentration of Yb2O3 is greater than the critical value, the area of the absorption cress-section of Er^3＋ ions near 1535 nm has a linear increase with the increase of Yb2O3 concentration. Yb^3＋ co-doping makes the PL intensity to enhance and the PL spectra of Er^3＋ ions to broaden considerably. Quantitative analysis indicates that the inverse transfer energy from the acceptor to the donor does increase with the increase of Yb2O3 concentration. However, it could not be the dominaing factor causing the saturation of PL intensity. We ascribe the saturation of PL intensity to be due to the decrease of PL quantum efficiency and the saturation of excited states in the system caused by the increase of sensitizers. The sensitization of Yb^3＋ ions also results in the increase of Yb^3＋ -^2F5/2 and Er^3＋ -^4I11/2 populations, which promotes the cooperative up-conversion between Er^3＋ and Yb^3＋ ions.

关 键 词：Er/Yb共掺 光致荧光 能量传递 合作上转换 

分 类 号：O482.31[理学—固体物理]