Er/Yb共掺体系的光致荧光行为及相关物理过程研究

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⁴ 关键词： Er/Yb共掺 光致荧光 能量传递 合作上转换

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

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 cross-section of Er³⁺ ions near 1535 nm has a linear increase with the increase of Yb₂O₃ concentration. Yb³⁺ co-doping makes the PL intensity to enhance and the PL spectra of Er³⁺ 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 Yb³⁺ ions also results in the increase of Yb³⁺-²F_5/2 and Er³⁺-⁴I_11/2 populations, which promotes the cooperative up-conversion between Er³⁺ and Yb³⁺ ions.