Upconversion photoluminescence and optical temperature sensing properties of PbNb2O6:Yb3+, Ln3+ (Ln3+=Er3+/Ho3+) ceramics

Through conventional solid-state sintering process, PbNb2O6:Yb3+, Ln3+ (Ln3+=Er3+/Ho3+) ceramics have been fabricated. The structural information of synthesized ceramics was obtained via X-ray diffraction. Scanning electron microscopy was utilized to investigate their morphological properties. The investigation of upconversion photoluminescence properties of the synthesized ceramics was conducted by analyzing upconversion emission spectra upon excitation with 980 nm light. Power dependence studies confirmed the presence of two-photon absorption processes in both PbNb2O6:Yb3+, Er3+ and PbNb2O6:Yb3+, Ho3+ ceramics. Temperature-dependent experiments from 303 K to 513 K demonstrated significant variations in emission intensities and fluorescence intensity ratios (FIR), enabling the assessment of temperature changes. The absolute sensitivity of PbNb2O6 ceramic co-doped with Yb3+, Er3+ ions reached its maximum value of 0.0056 K-1 at 513 K, while the maximum relative sensitivity of 0.697% K-1 was recorded at 339 K. For PbNb2O6 ceramic co-doped with Yb3+, Ho3+ ions, the maximum values of absolute and relative sensitivities were 0.048 K-1 and 0.8% K-1 at 513 K and 473 K, respectively. These results highlight the potential applications of PbNb2O6:Yb3+, Ln3+ (Ln3+=Er3+/Ho3+) ceramics in advanced temperature sensing based on photoluminescence.