Phase transition, size control and color tuning of NaREF4:Yb3+, Er3+ (RE = Y, Lu) nanocrystals.
Phase transition, size control and color tuning of NaREF4:Yb3+, Er3+ (RE = Y, Lu) nanocrystals.
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DOI：
10.1039/c3nr34282d
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发表时间：
2013-03
期刊：
影响因子：
6.7
通讯作者：
Jing Wang;Hongwei Song;Wen Xu;Biao Dong;Sai Xu;Boting Chen;Wei Yu;Shuang Zhang
中科院分区：
文献类型：
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作者：
Jing Wang;Hongwei Song;Wen Xu;Biao Dong;Sai Xu;Boting Chen;Wei Yu;Shuang Zhang
通过控制上转换纳米晶的尺寸和结构来精细调节上转换性能，提高其效率具有重要意义。最近，有报道称，在980 nm激发下，NaLuF4：Yb（3+），Er（3+）UCNCs的UC发光（UCL）强度与最有效的NaYF4：Yb（3+），Er（3+）相比可以得到极大的改善。本文首先研究了溶剂热法制备的NaREF_4：Yb（3+），Er（3+）（RE = Y，Lu）UCNCs的尺寸控制和相变性质。讨论了NaLuF_4：Yb（3+），Er（3+）的UCL强度是否普遍优于NaYF_4：Yb（3+），Er（3+）UCNCs。系统地讨论了NaREF 4：Yb（3+），Er（3+）系列晶体的晶相、粒径、掺杂浓度和声子能量等对晶体颜色的影响。有趣的是，在重掺杂立方相NaREF 4：Yb（3+），Er（3+）中，随着粒径的减小，UCL的颜色从红色变为绿色，而在六方相中，UCL的颜色从绿色变为红色。提出了一个单元模型来解释NaREF4：Yb（3+），Er（3+）晶体的相依赖和尺寸依赖的颜色调谐UCL行为。
It is important to finely tune the upconversion (UC) properties through controlling size and structure of upconversion nanocrystals (UCNCs) and improve their efficiency. Recently, it was reported that the UC luminescence (UCL) intensity of NaLuF4:Yb(3+), Er(3+) UCNCs could be tremendously improved compared to the most efficient NaYF4:Yb(3+), Er(3+) under 980 nm excitation. In this paper, we first studied the varied size control and phase transition properties of NaREF4:Yb(3+), Er(3+) (RE = Y, Lu) UCNCs prepared by the solvothermal method. Then, we discussed if the UCL intensity of NaLuF4:Yb(3+), Er(3+) could be universally improved over that of NaYF4:Yb(3+), Er(3+) UCNCs. Furthermore, the color tuning properties of the NaREF4:Yb(3+), Er(3+) family on crystalline phase, particle size, doping concentration and phonon energy were systemically discussed. It is very interesting to observe that in heavily doped cubic NaREF4:Yb(3+), Er(3+), the color of UCL changed from red to green with decreasing particle size, while on the contrary, in hexagonal phase the color of UCL changed from green to red. A unit model was proposed to explain the phase-dependent, size-dependent color tuning UCL behavior of NaREF4:Yb(3+), Er(3+).