采用传统高温固相法制备了GdNbO4∶10%Yb3+,x%Er3+荧光粉。利用XRD对样品的晶体结构进行了分析, 结果表明所得的样品为纯相。在980 nm 光纤激光器激发下, 测量了样品的上转换发射光谱, 实验发现样品发生了浓度猝灭。利用荧光强度比(FIR) 方法研究了GdNbO4∶Yb3+/Er3+荧光粉的温度传感特性, 结果表明灵敏度随温度的升高先增大后减小。建立了Er3+的两个绿色发射能级的温度猝灭物理模型并用其成功解释了样品的绿色上转换发光温度猝灭现象。

A series of Er3+/Yb3+ co-doped phosphors with various Er3+ concentrations were synthesized via the conventional high temperature solid state method. The crystal structure of the obtained phosphor was analyzed by means of X-ray diffraction (XRD). The results show that the doping concentration do not evoke the change in crystal structure. The upconversion emission spectra for the phosphors doped with various Er3+ concentrations were measured upon 980 nm excitation under the same experimental conditions. The results show that the concentration quenching occurs at a higher concentration. The optical temperature sensing properties based on the fluorescence intensity ratio (FIR) method were discussed by analyzing intensities ratio of 2H11/2 and 4S3/2 emission with the temperature. It is observed that the sensitivity increases first and then decreases with the increase of temperature, and the sensitivity is the highest at 180 ℃. A physical model involving radiative/nonradiative transitions and thermal excitation of 2H11/2 and 4S3/2 emission is established, and the temperature quenching of the phenomenon is explained successfully.