Importance of Suppression of Yb3+ De-Excitation to Upconversion Enhancement in beta-NaYF4: Yb3+/Er3+@beta-NaYF4 Sandwiched Structure Nanocrystals

	Importance of Suppression of Yb3+ De-Excitation to Upconversion Enhancement in beta-NaYF4: Yb3+/Er3+@beta-NaYF4 Sandwiched Structure Nanocrystals
	Xiang, G. T.; J. H. Zhang; Z. D. Hao; X. Zhang; G. H. Pan; Y. S. Luo; W. Lu and H. F. Zhao
	2015
发表期刊	Inorganic Chemistry
卷号	54 期号:8 页码:3921-3928
摘要	Nanosized Yb3+ and Er3+ co-doped beta-NaYF4 cores coated with multiple beta-NaYF4 shell layers were synthesized by a solvothermal process. X-ray diffraction and scanning electron microscopy were used to characterize the crystal structure and morphology of the materials. The visible and near-infrared spectra as well as the decay curves were also measured. A 40-fold intensity increase for the green upconversion and a 34-fold intensity increase for the red upconversion were observed as the cores are coated with three shell layers. The origin of the upconversion enhancement was studied on the basis of photoluminescence spectra and decay times. Our results indicate that the upconversion enhancement in the sandwiched structure mainly originates from the suppression of de-excitation of Yb3+ ions. We also explored the population of the Er(3+)4F(9/2) level. The results reveal that energy transfer from the lower intermediate Er(3+)4I(13/2) level is dominant for populating the Er(3+)4F(9/2) level when the nanocrystal size is relatively small; however, with increasing nanocrystal size, the contribution of the green emitting Er(3+)4S(3/2) level for populating the Er(3+)4F(9/2) level, which mainly comes from the cross relaxation energy transfer from Er3+ ions to Yb3+ ions followed by energy back transfer within the same Er3+-Yb3+ pair, becomes more and more important. Moreover, this mechanism takes place only in the nearest Er3+-Yb3+ pairs. This population route is in good agreement with that in nanomaterials and bulk materials.
收录类别	SCI
文献类型	期刊论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/55481
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	Xiang, G. T.,J. H. Zhang,Z. D. Hao,et al. Importance of Suppression of Yb3+ De-Excitation to Upconversion Enhancement in beta-NaYF4: Yb3+/Er3+@beta-NaYF4 Sandwiched Structure Nanocrystals[J]. Inorganic Chemistry,2015,54(8):3921-3928.
APA	Xiang, G. T..,J. H. Zhang.,Z. D. Hao.,X. Zhang.,G. H. Pan.,...&W. Lu and H. F. Zhao.(2015).Importance of Suppression of Yb3+ De-Excitation to Upconversion Enhancement in beta-NaYF4: Yb3+/Er3+@beta-NaYF4 Sandwiched Structure Nanocrystals.Inorganic Chemistry,54(8),3921-3928.
MLA	Xiang, G. T.,et al."Importance of Suppression of Yb3+ De-Excitation to Upconversion Enhancement in beta-NaYF4: Yb3+/Er3+@beta-NaYF4 Sandwiched Structure Nanocrystals".Inorganic Chemistry 54.8(2015):3921-3928.

条目包含的文件		下载所有文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
Xiang-2015-Importanc（583KB）	期刊论文	作者接受稿	开放获取	CC BY-NC-SA	浏览下载