Optical thermometry based on up-conversion luminescence of self-crystallized glass-ceramics containing GdOF: Yb³⁺, Er³⁺ nanocrystals

Optical temperature measurement overcomes certain limitations associated with traditional contact methods. Fluorescence Intensity Ratio (FIR) technology is often used in optical temperature measurement. Furthermore, selecting appropriate host materials can increase temperature-sensing sensitivity. The conventional melt quenching method forms transparent glass-ceramics (GCs) efficiently precipitated with GdOF: Yb³⁺, Er³⁺ nanocrystals. X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) are used to examine and validate the structural and morphological characteristics of the nanocrystals. Under 980 nm excitation, the impacts of laser pumping power of GCs, Yb³⁺/Er³⁺ concentration, and heat treatment temperature on the upconversion luminescence properties are systematically examined. The sensitivity of temperature sensing is evaluated through the FIR of non-thermally coupled levels (NTCLs) and thermally coupled levels (TCLs). At 300 K, the relative sensitivity of the GCs samples increased to 1.06% K^− 1, indicating that glass-ceramics containing GdOF: Yb³⁺, Er³⁺ nanocrystals could be a viable option for temperature sensing.