YOF: Yb3+, Er3+ powders with rhombohedral phase were successfully synthesized by using a modified sol–gel method with calcinating under a temperature range between 400 °C and 600 °C. A systematic study on the temperature-dependent morphology and spectroscopic properties of rhombohedral YOF: Yb3+, Er3+ powders have been performed. The YOF: Yb3+, Er3+ powders that prepared at 400 °C and 500 °C exhibit a plate growth habit, while the powder that prepared at 600 °C shows a sintering property. When excited by 980 nm laser beam, all of the rhombohedral YOF: Yb3+, Er3+ powders show efficient red light emission with light wavelength ranging from 630 nm to 700 nm. The upconversion mechanism and luminescence decay properties were discussed in detail.
Rare earth luminescent materials have attracted extensive attention in the biomedical field as noncontact temperature monitoring devices with microscopic resolution due to their properties in the visible and near-infrared regions. At the application level, it is required to have a certain temperature monitoring capability in the near-infrared region II window to enhance the tissue penetration depth. Here, two kinds of YOFs: Er 3 + , Yb 3 + were prepared by co-precipitation and hydrothermal method, and the luminescence was enhanced by ion doping. An Er 3 + -based ratiometric nanothermometer of 4 F 9 ∕ 2 → 4 I 1 5 ∕ 2 (672 nm, upconversion luminescence) to 4 I 1 3 ∕ 2 → 4 I 1 5 ∕ 2 (1580 nm/1566 nm, NIR II downshifting luminescence) were designed with the Stark energy level. When doped with 2% Zn 2 + , the relative temperature sensitivity of YOF prepared by co-precipitation method was improved from 0.30% ∘ C − 1 (30 ∘ C) to 0.59% ∘ C − 1 (30 ∘ C), expanding its use as a temperature monitoring device possibility. The temperature sensitivity of YOF prepared by hydrothermal method was 1.01% ∘ C − 1 (30 ∘ C). Finally, the NIR II luminescence of the prepared nanothermometer was used as a control for temperature monitoring of heating sites in mice. The results showed that it can distinguish heating site from control site and no significant cytotoxicity or damage to the tissues was revealed, indicating its broad prospects in the biomedical field and other temperature monitoring scenarios in the future.
危险品化学品经营许可证（带存储）