Upconversion luminescence and optical thermometry properties of glass ceramics embedded with YbOF: Er³⁺ nanocrystals

Transparent glass ceramics embedded with YbOF: Er³⁺ nanocrystals were successfully prepared by melt quenching and cooling methods. The structure and morphology of the YbOF nanocrystals were confirmed by X-ray diffraction, selected area electron diffraction, and transmission electron microscopy. The significant enhancement of upconversion luminescence confirms the doping of Er³⁺ into the precipitated YbOF nanocrystals. Furthermore, the temperature dependence of the upconversion luminescence was systematically investigated using the fluorescence intensity ratio (FIR) technique under 980 nm excitation. The FIR of the two thermally coupled energy levels of Er³⁺ ion was validated to be suitable used as temperature probes. The maximum thermal relative sensitivity is about 1.02% K^− 1 at 300 K. The results indicate that glass ceramics embedded with YbOF: Er³⁺ nanocrystals can be used as candidates for temperature sensing.