Highly sensitive optical thermometer based on FIR technique of transparent NaY2F7:Tm3+/Yb3+ glass ceramic

Non-contact temperature sensors based on up-conversion photoemission with quick response and in situ monitoring exhibits scientific and technological potential. However, to achieve highly efficient upconversion and good temperature sensing performance from doped disordered glass matrix has led to limited success. Here, we report a nano-structured NaY2F2:Yb3+/Tm3+ glass ceramic for intense upconversion in the first bio-window and sensitive optical response on temperature. Evidenced by detailed structural and optical characterization, the incorporation of Yb3+/Tm3+ into NaY2F2 nanocrystals results in the greatly enhanced and long-lived photoluminescence with noteworthy Stark splitting. More interestingly, the emission intensity ratio of thermally coupled F-3(2,3) -> H-3(6) and (1)G(4) -> F-3(4) transition of Tm3+ is highly temperature dependent and repeatable due the protection of silicate glass network. Thus, NaY2F2:Yb3+/Tm3+ glass ceramic shows excellent temperature sensing performances, including high sensitivity, and excellent repeatability. In particular, the maximal relative and absolute sensitivity reach 1.63 %K-1 (415 K) and 10.01 %K-1 (567 K), respectively. These results reveal that Yb3+/Tm3+ co-doped NaY2F7 GC could be promising in the application of up-converting materials for high performance optical temperature sensor. (C) 2020 Elsevier B.V. All rights reserved.