Synthesis of Multicolor Core/Shell NaLuF₄:Yb(3+)/Ln(3+)@CaF₂ Upconversion Nanocrystals.
Synthesis of Multicolor Core/Shell NaLuF₄:Yb(3+)/Ln(3+)@CaF₂ Upconversion Nanocrystals.
复制标题
多色核/壳NaLuF4:Yb3 /Ln(3)@CaF2上转换纳米晶的合成
DOI：
10.3390/nano7020034
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发表时间：
2017-02-07
期刊：
影响因子：
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通讯作者：
Chen G
中科院分区：
文献类型：
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作者：
Li H;Hao S;Yang C;Chen G
从有效的主体晶格合成高质量的分级核/壳纳米晶体的能力对于实现从生物成像到太阳能电池的应用的有效光子上转换是重要的。本文以氟化镥钠（NaLuF 4）为基质晶格，采用一种新的方法制备了具有“核@壳”结构的α-NaLuF 4：Yb 3 +/Ln 3 +@CaF2（Ln = Er，Ho，Tm）上转换纳米晶体（UCNCs）。我们采用液-固溶液法合成了纯立方相的NaLuF 4核，并采用热分解法在核UCNCs上外延生长了氟化钙（CaF 2）壳，得到了尺寸为15.6 ± 1.2 nm的立方核/壳纳米晶体（核~9 ± 0.9 nm，壳~3.3 ± 0.3 nm）。我们发现，这些核/壳UCNCs可以发射激活剂定义的荧光发射高达约772倍的效率比核心纳米晶体由于有效抑制表面相关的淬灭效应。我们的研究结果提供了一个新的范例异质核/壳结构的增强的上转换发光胶体纳米晶体。
The ability to synthesize high-quality hierarchical core/shell nanocrystals from an efficient host lattice is important to realize efficacious photon upconversion for applications ranging from bioimaging to solar cells. Here, we describe a strategy to fabricate multicolor core @ shell α-NaLuF4:Yb3+/Ln3+@CaF2 (Ln = Er, Ho, Tm) upconversion nanocrystals (UCNCs) based on the newly established host lattice of sodium lutetium fluoride (NaLuF4). We exploited the liquid-solid-solution method to synthesize the NaLuF4 core of pure cubic phase and the thermal decomposition approach to expitaxially grow the calcium fluoride (CaF2) shell onto the core UCNCs, yielding cubic core/shell nanocrystals with a size of 15.6 ± 1.2 nm (the core ~9 ± 0.9 nm, the shell ~3.3 ± 0.3 nm). We showed that those core/shell UCNCs could emit activator-defined multicolor emissions up to about 772 times more efficient than the core nanocrystals due to effective suppression of surface-related quenching effects. Our results provide a new paradigm on heterogeneous core/shell structure for enhanced multicolor upconversion photoluminescence from colloidal nanocrystals.