Er^(3+)/Yb^(3+)共掺杂SrF_2纳米晶的合成及上转换发光特性

Synthesis and Up-Conversion Luminescence Properties of Er^(3+)/Yb^(3+) Codoped SrF_2 Nanocrystals

利用水热法以聚乙二醇作为分散剂合成了Er3+和Yb3+共掺的SrF2纳米晶。在980 nm半导体激光器激发下,研究了不同Er3+离子掺杂浓度对发光性能的影响,确定了最佳掺杂浓度比,讨论了退火温度对样品发光的影响及样品的协作敏化和声子辅助共振能量传递的上转换发光机制。用X射线衍射和透射电镜对样品的结构和粒度进行了分析。研究结果表明:用水热法在180℃保温13 h下,合成的样品粒径约为50 nm;当cYb3+∶cEr3+=4∶1,而对Er3+掺杂浓度为1.3mol%时,样品上转换发光强度达到最强。

Nanocrystals of up-conversion phosphor Er^3＋ and Yb^3＋ co-doped SrF2 were prepared by hydrothermal method using Polyethylene Glycol as dispersant. Under 980 nm laser diode excitation, the impact of different concentration of Er^3＋ ions on the up-conversion luminescence intensity was discussed. The up-conversion mechanism and processes were also analyzed. Ground state absorption, excitation state absorption and energy transfer were used in discussing the up-conversion mechanism of the sample and up-conversion mechanism models of sample was discussed in detail. The sample was characterized by transmission electron microscopy （TEM） and X-ray diffraction （XRD）. The results showed that the sample was successfully synthesized by hydrothermal method at 180 ℃ and the average grain size is about 50 nm. When CYb^3＋：CEr^3＋ is 4：1 and the doped concentration of Er^3＋ ions is 1.3mol%, the upconversion intensity get the most.