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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (21): 2439-2444. 上一篇    

研究简报

NaYF4∶Er3＋, Yb3＋纳米晶的液相合成

贾若琨*,a 杨 珊a 李翠霞a 闫永楠a 白玉白b

  

  1. (a东北电力大学化学工程学院 吉林 132012)
    (b吉林大学化学学院 长春 130061)

  • 投稿日期:2008-04-18 修回日期:2008-06-11 发布日期:2008-11-14
  • 通讯作者: 贾若琨

Liquid Preparation of Soluble NaYF4∶Er3＋, Yb3＋ Nanocrystals

JIA, Ruo-Kun *,a YANG, Shan a LI, Cui-Xia a YAN, Yong-Nan a BAI, Yu-Bai b   

  1. (a College of Chemical Engineering, Northeast Dianli University, Jilin 132012)
    (b College of Chemistry, Jilin University, Changchun 130061)
  • Received:2008-04-18 Revised:2008-06-11 Published:2008-11-14

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采用丙三醇液相结晶法制备了NaYF4∶Er3＋, Yb3＋上转换纳米晶, 合成步骤被简化. 常温下, 用980 nm的红外激光激发可以观察到很强的绿光、红光发射, 用荧光光谱仪记录了该上转换光谱. X射线粉末衍射(XRD)结果表明, 该方法制备NaYF4∶Er3＋, Yb3＋纳米晶属于立方混合六方晶系. 研究了纳米晶的上转换发光机理, 根据晶体场理论对Er3＋的两个上转换能级进行了Stark分裂计算, 对两个能级之间的谱线进行了归属, 进一步证实了980 nm光子激发Er3＋离子的上转换机理, 一个是连续吸收两个980 nm光子的过程(激发态吸收), 另一个是吸收980 nm光子后, 电子转移到亚稳态能级, 然后再吸收980 nm光子过程(能量转移上转换).

关键词: NaYF4∶Er3＋, Yb3＋, 上转换, Stark分裂, 液相结晶

The NaYF4∶Er3＋, Yb3＋ nanocrystals have been prepared by liquid crystallization from glycerol. Red at 660 nm and green at 550 nm upconversion emissions were observed from NaYF4∶Er3＋, Yb3＋ nanocrystals under 980 nm excitation. The X-ray diffraction patterns confirm the nanocrystals are cubic and hexagonal. The mechanism of nanocrystal upconvertion has been studied. The Stark splits of two excitated states of Er3＋ have been calculated based on theory of crystallization fields. The results confirm the upconverted mechanisms in the NaYF4∶Er3＋, Yb3＋ nanocrystals are due to two processes, one is a consecutive absorption of two 980 nm photon process, and the other process is that electrons transfer to substeady states after absorption of 980 nm photons, then absorb 980 nm photons.

Key words: NaYF4∶Er3＋, Yb3＋, upconversion, Stark split, crystallization from liquid