Simultaneous size adjustment and upconversion luminescence enhancement of β-NaLuF4:Yb3+/Er3+,Er3+/Tm3+ microcrystals by introducing Ca2+ for temperature sensing
Simultaneous size adjustment and upconversion luminescence enhancement of β-NaLuF4:Yb3+/Er3+,Er3+/Tm3+ microcrystals by introducing Ca2+ for temperature sensing
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DOI：
10.1039/c8ce00127h
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发表时间：
2018-04
期刊：
影响因子：
3.1
通讯作者：
Aihua Zhou;F. Song;Yingdong Han;Feifei Song;Dandan Ju;Xueqin Wang
中科院分区：
文献类型：
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作者：
Aihua Zhou;F. Song;Yingdong Han;Feifei Song;Dandan Ju;Xueqin Wang
采用水热法在较低的温度（180 °C）下，仅用2 h就得到了β-NaLuF_4：Yb ~（3+）/Er ~（3+）微晶。通过引入Ca ~（2+）离子，可以同时实现微晶尺寸的可调和上转换发光的增强。结果表明，当Ca ~（2+）浓度从0增加到20 mol%时，圆盘的平均直径增大，高度减小。但随着Ca ~（2+）浓度的进一步增加，则相反。这一结果可以归因于F−在不同晶面上的覆盖效应。更重要的是，掺杂40mol%Ca ~（2+）的β-NaLuF_4：Yb ~（3+）/Er ~（3+）样品的绿色和红色上转换发光强度分别是未掺杂样品的7.5倍和7.9倍。此外，Ca ~（2+）的掺杂还可以扩展到β-NaLuF_4：Er ~（3+）/Tm ~（3+），以增强上转换发光。最后，重点研究了β-NaLuF 4：20 Yb 3 +/2 Er 3 +/40 Ca 2+（mol%）和无Ca 2+样品的温度依赖性上转换发光特性。在120 K时，β-NaLuF 4：20 Yb 3 +/2 Er 3 +/40 Ca 2+（mol%）的最大灵敏度（0.00040 K−1）高于β-NaLuF 4：20 Yb 3 +/2 Er 3+（mol%）的最大灵敏度（0.00021 K−1），表明含Ca 2+的样品具有应用于温度传感的潜力。
β-NaLuF4:Yb3+/Er3+ microcrystals have been obtained through a facile hydrothermal method at a relatively low temperature (180 °C) within only two hours. By introducing Ca2+ ions, the microcrystals can simultaneously be tunable in size and realize upconversion luminescence enhancement. It is found that when the concentration of Ca2+ ions increases from 0 to 20 mol%, the average diameter of disks increases while the height decreases. However, with the concentration of Ca2+ further increasing, the opposite is true. This result can be ascribed to the capping effect of F− on the different crystal faces. More importantly, the upconversion luminescence intensities of green and red emissions of β-NaLuF4:Yb3+/Er3+ with 40 mol% Ca2+ ion doping are about 7.5 and 7.9 times higher than those of the sample without Ca2+ doping, respectively. Besides, the Ca2+ doping can also be extended to β-NaLuF4:Er3+/Tm3+ for enhancement of the upconversion luminescence. Eventually, emphasis will be on the temperature-dependent upconversion properties of β-NaLuF4:20Yb3+/2Er3+/40Ca2+ (mol%) and Ca2+-free samples. The maximum sensitivity of β-NaLuF4:20Yb3+/2Er3+/40Ca2+ (mol%) (0.00040 K−1) is higher than that of β-NaLuF4:20Yb3+/2Er3+ (mol%) (0.00021 K−1) at 120 K under the same excitation pump power of 1 W, indicating that the sample with Ca2+ has potential for application to temperature sensing.