上转换材料LiY(MoO4)2:Yb3+/Er3+的光学特性以及温度传感特性的研究

采用中温固相反应法合成了发光材料LiY （MoO₄）₂：Yb³⁺/Er³⁺，材料具有明显的上转换发光特性.通过X射线衍射仪、荧光光谱对荧光粉的晶体结构以及发光学特性进行了研究.在980 nm激光的激发下，LiY （MoO₄）₂：Yb³⁺/Er³⁺在500~575 nm波长范围内出现很强的绿色发射带，主要是源自Er³⁺离子²H_11/2/⁴S_3/2→⁴I_15/2的能级辐射跃迁.研究发现其在不同功率的激发下能实现光色调控.在298~513 K温度范围内，通过测量其在²H_11/2（1）→⁴I_15/2和⁴S_3/2（1）→⁴I_15/2处的荧光强度比，数据拟合图像表明²H_11/2（1）/⁴S_3/2（1）热耦合能级上的布居数遵循玻尔兹曼分布，相对灵敏度在298 K达到最大值1.785% K^-1，绝对灵敏度在约473 K达到最大值263.20×10^-4 K^-1，并且热能级²H_11/2（1）/⁴S_3/2（1）之间的能隙ΔE为756.71±27.48 cm^-1.基于以上分析，LiY （MoO₄）₂：Yb³⁺/Er³⁺荧光粉在温度传感器上具有很好的前景.

The Temperature-Sensor and Optical Properties of Up-Conversion Phosphor LiY(MoO4)2:Yb3+/Er3+

The phosphors LiY(MoO₄)₂:Yb³⁺/Er³⁺ with remarkable up-conversion emission character were synthesized by means of high-temperature solid state reaction method. Experiments were carried out to determine the crystal structure, up-conversion emission optical properties and temperature sensing of the phosphors. Under 980 nm laser, the LiY(MoO₄)₂:Yb³⁺/Er³⁺ exhibits an intensive green emission bands which can be assigned to ²H_11/2/⁴S_3/2→⁴I_15/2 transitions. The temperature sensing properties were studied by measuring the fluorescence intensity ratio of the ²H_11/2(1) and ⁴S_3/2(1) emitting energy levels in the temperature range from 298 to 513 K. The maximum relative sensitivity was 1.785% K^-1 at 298 K and the maximum absolute sensitivity reach to 263.20×10^-4 K^-1 at 473 K, and the calculated energy gap ΔE between ²H_11/2(1) and ⁴S_3/2(1) levels was 756.71±27.48 cm^-1, suggesting that the present phosphor is a suitable candidate for optical temperature sensors.