Up-Converting Luminescence and Temperature Sensing of Er³⁺/Tm³⁺/Yb³⁺ Co-Doped NaYF₄ Phosphors Operating in Visible and the First Biological Window Range

• 發表在: Nanomaterials
• Main Authors: Jingyun Li, Yuxiao Wang, Xueru Zhang, Liang Li, Haoyue Hao
• 格式: Article
• 語言: 英语
• 出版: MDPI AG 2021-10-01
• 主題: luminescent materials; rare earth doped materials; optical thermometry; luminescence intensity ratio
• 在線閱讀: https://www.mdpi.com/2079-4991/11/10/2660

Accurate and reliable non-contact temperature sensors are imperative for industrial production and scientific research. Here, Er³⁺/Tm³⁺/Yb³⁺ co-doped NaYF₄ phosphors were studied as an optical thermometry material. The typical hydrothermal method was used to synthesize hexagonal Er³⁺/Tm³⁺/Yb³⁺ co-doped NaYF₄ phosphors and the morphology was approximately rod-like. The up-conversion emissions of the samples were located at 475, 520, 550, 650, 692 and 800 nm. Thermo-responsive emissions from the samples were monitored to evaluate the relative sensing sensitivity. The thermal coupled energy level- and non-thermal coupled energy level-based luminescence intensity ratio thermometry of the sample demonstrated that these two methods can be used to test temperature. Two green emissions (520 and 550 nm), radiated from ²H_11/2/⁴S_3/2 levels, were monitored, and the maximum relative sensing sensitivities reached to 0.013 K⁻¹ at 297 K. The emissions located in the first biological window (650, 692 and 800 nm) were monitored and the maximum relative sensing sensitivities reached to 0.027 (<i>R</i>_692/650) and 0.028 K⁻¹ (<i>R</i>_692/800) at 297 K, respectively. These results indicate that Er³⁺/Tm³⁺/Yb³⁺ co-doped NaYF₄ phosphors have potential applications for temperature determination in the visible and the first biological window ranges.