Non-contact thermometry based on upconversion luminescence from lanthanide-doped nanoparticles is the best choice when temperature probes with higher precision, accuracy, sensitivity, and spatial resolution are required. Here, LaOF:Yb³⁺,Ho³⁺ upconversion nanoparticles (UCNPs) were demonstrated to be thermometers with a high sensitivity and thermal stability within the temperature range of 303–673 K. Microwave-assisted hydrothermal synthesis was used to obtain these rod-shaped UCNPs with a trigonal crystal structure. LaOF:Yb³⁺,Ho³⁺ UCNPs displayed green emissions due to the thermally-coupled levels (⁵F₄, ⁵S₂) and red emissions from the Stark-split sublevels of the ⁵F₅ energy level belonging to Ho³⁺ under 980 nm continuous-wave laser irradiation. The upconversion emission originating from these transitions were remarkably sensitive to the temperature variation. Their fluorescence intensity ratios were explored to evaluate their relative (S_R) and absolute (S_A) sensitivities. Optical heating induced by continuous laser irradiation was also examined to assess the degradation of the luminescence caused by laser exposure.

当需要具有更高精度、准确度、灵敏度和空间分辨率的温度探头时，基于镧系元素掺杂纳米粒子的上转换发光的非接触式测温是最佳选择。在这里，LaOF:Yb ³⁺ ,Ho ³⁺上转换纳米粒子 (UCNPs) 被证明是在 303–673 K 的温度范围内具有高灵敏度和热稳定性的温度计。微波辅助水热合成用于获得这些棒-具有三角形晶体结构的异型 UCNP。LaOF:Yb ³⁺ ,Ho ³⁺ UCNPs 由于热耦合能级 ( ⁵ F ₄ , ⁵ S ₂)和980 nm连续波激光照射下属于Ho ^3+的5 F ₅能级的斯塔克分裂子能级的红光发射。源自这些转变的上转换发射对温度变化非常敏感。研究了它们的荧光强度比以评估它们的相对 (SR ₎和绝对 (SA ₎灵敏度。还检查了由连续激光照射引起的光热，以评估由激光照射引起的发光退化。