β-NaYF 4 :Yb, Er at β-NaYF 4 core/shell nanocrystals with significantly enhanced upconversion fluorescence by a successive two-step hot-injection approach
β-NaYF 4 :Yb, Er at β-NaYF 4 core/shell nanocrystals with significantly enhanced upconversion fluorescence by a successive two-step hot-injection approach
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DOI：
10.1049/mnl.2013.0398
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发表时间：
2013-10
影响因子：
1.3
通讯作者：
Qing Tian;Ke Tao;K. Sun
中科院分区：
文献类型：
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作者：
Qing Tian;Ke Tao;K. Sun
表面钝化是提高小尺寸上转换纳米材料发光性能的常用方法。本文采用两步热注入法合成了核/壳结构的NaYF 4。利用透射电子显微镜、X射线衍射和X射线光电子能谱等测试手段证明了β-NaYF 4：Yb，Er在β-NaYF 4上的成功制备。核尺寸和壳厚度分别由稳定剂和前体添加量控制。与原始核纳米晶体相比，所得核/壳结构纳米晶体的上转换效率可以提高超过100倍。显着的荧光增强归因于在升高的温度下连续注射的前体。
Surface passivation is a general approach to enhance the luminescence of small-scaled size upconversion nanomaterials. In this reported work, a two-step hot-injection method was developed to synthesise core/shell structured NaYF4. A transmission electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy were employed to prove the successful fabrication of β-NaYF4:Yb, Er at β-NaYF4. Core size and shell thickness were controlled by the amount of stabiliser and precursors addition, respectively. The upconversion efficiency of the resultant core/shell structured nanocrystals could be improved more than a 100-fold by comparison with the original core nanocrystals. Significant fluorescence enhancement was ascribed to the successive injection of precursors at elevated temperature.