Tunable green/red dual-mode luminescence via energy management in core-multishell nanoparticles
Tunable green/red dual-mode luminescence via energy management in core-multishell nanoparticles
复制标题
通过核-多壳纳米粒子的能量管理可调谐绿/红双模发光
DOI：
10.1016/j.matdes.2018.04.054
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发表时间：
2018
影响因子：
8.4
通讯作者：
Li Guangshe
中科院分区：
文献类型：
--
作者：
Leng Zhihua;Li Liping;Zhang Dan;Li Guangshe
Tb~(3+)/Eu~(3+)离子的上转换发光一般是通过一个复杂的能量传递过程(Yb~(3+)→ Tm~(3+)→ Gd~(3+)+→ Ln~(3+)，Ln = Tb/Eu)实现的，这使得相关的能量管理变得相当困难，不可避免地会导致Tm~(3+)的不纯蓝色发光。在这项工作中，设计了一种简单而合理的策略来将Eu3+/Tb3+离子的双模发光集成到NaGdF4:Yb/Eu@NaGdF4:Ce@NaGdF4:Yb/Tb@NaYF4core-multishell纳米结构中。研究发现，通过NaGdF4@NaGdF4界面的下转换能量转移被限制在大约2 nm的窄空间范围内。对于上转换模式，决定Eu3+发射强度的主要因素是第二壳层NaGdF4：Yb/Tb与芯层NaGdF4：Yb/Eu的摩尔比，这与以前报道的各向异性过滤效应不同。最终，通过简单地改变NaGdF4：Yb/Tb的内壳厚度，获得了可调的双模发射颜色。本文报道的将Eu3+/Tb3+的双模发光集成到能量管理中的策略使人们能够为许多重要的应用设计新的发光材料。
Achieving up-conversion luminescence from Tb3+/Eu3+ions was generally via a complicated energy transfer process (Yb3+→ Tm3+→ Gd3+→ Ln3+, Ln = Tb/Eu), which makes the relevant energy management rather difficult and inevitably results in impure blue luminescence of Tm3+. In this work, a facile and rational strategy is designed to integrate dual-mode luminescence from Eu3+/Tb3+ions into NaGdF4:Yb/Eu@NaGdF4:Ce@NaGdF4:Yb/Tb@NaYF4core-multishell nanostructure. It is found that the down-conversion energy transfer across NaGdF4@NaGdF4interface is confined in a narrow space region of approximately 2 nm. For the up-conversion mode, the primary factor that dominates the emission intensity of Eu3+is determined to be the molar ratio of NaGdF4:Yb/Tb component in the second shell to NaGdF4:Yb/Eu one in the core, which differs from the anisotropic filtration effect previously reported. Eventually, tunable dual-mode emission colors were achieved through simply varying the inner shell thickness of NaGdF4:Yb/Tb. The strategy of integrating dual-mode luminescence of Eu3+/Tb3+reported here for energy management allows one to design new luminescence materials for many important applications.