中文摘要：

利用溶剂热法制备了Yb^3＋、Er^3＋共掺的NaYF4上转换发光纳米材料。实验结果表明，不同F^-离子对纳米晶的晶型和粒径尺寸起着重要的作用。低F^-离子浓度下，NaYF4纳米材料的粒径尺寸随F-离子浓度的增加逐渐变小且趋于均一；高F-离子浓度下，六方晶相的形成受到抑制，上转换纳米晶出现团聚现象。在一定浓度范围内，F-离子的浓度有利于促进荧光发射。同时F^-离子浓度对荧光寿命也有显著的影响。

英文摘要：

Up-conversion luminescent NaYF4：Yb^3＋/Er^3＋ nanomaterials were synthesized using a solvo-thermal method. It was determined that the size, morphology, and luminescence intensity of these nanoparticles can be controlled by varying the concentration of fluoride ions. Low reactant concentrations were found to always result in monodisperse, hexagonal nanocrystals, and to gradually and uniformly decrease the size of the NaYF4 nanocrystals. In contrast, at higher concentrations, the nanocrystals grow to form a mixed phase. Fluoride ion concentrations over a specific range tend to promote the fluorescence emission of the material and may also significantly affect the fluorescent lifetime.