In recent years, upconversion (UC) luminescence has attracted considerable attention because of its potential application in temperature measurement. In this work, LaNbO₄:Er³⁺/Yb³⁺ phosphors are synthesized using a solid-state method. The x-ray diffraction patterns show that the phosphors obtained exhibit a single monoclinic structure, and doping does not change the crystal structure. Intense green and red emissions are observed upon 980-nm excitation. The emission intensity varies with the doping concentration, and the best doping concentrations are 1 mol.% and 10 mol.% for Er³⁺ and Yb³⁺ ions, respectively. The possible luminescence mechanism is investigated based on the UC emission dependence on pump power. The temperature-sensing ability is also investigated based on the fluorescence intensity ratio between two thermally coupled levels ²H_11/2 and ⁴S_3/2. The maximum sensitivity achieved is 0.81% K⁻¹ at around 430 K, suggesting that the phosphor is a potential candidate for temperature sensing applications.

中文翻译：

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LaNbO 4：Yb 3+ / Er 3+荧光粉的上转换发光和光学温度传感特性

近年来，上转换（UC）发光由于其在温度测量中的潜在应用而备受关注。在这项工作中，使用固态方法合成了LaNbO ₄：Er ³⁺ / Yb ³⁺荧光粉。X射线衍射图表明，所获得的磷光体表现出单一的单斜晶结构，并且掺杂不会改变晶体结构。在980 nm激发下观察到强烈的绿色和红色发射光。发射强度随掺杂浓度而变化，对于Er ³⁺和Yb ³⁺，最佳掺杂浓度为1 mol。％和10 mol。％离子。基于UC发射对泵浦功率的依赖性，研究了可能的发光机理。还基于两个热耦合能级² H _11/2和⁴ S _3/2之间的荧光强度比来研究温度感测能力。在大约430 K时，获得的最大灵敏度为0.81％K ^-1，这表明磷光体是温度传感应用的潜在候选者。