Insight into the spectroscopic and thermometric properties of titanate phosphors via a novel co-excited laser system

摘要

An approach to enhance the photophysical properties of Er~(3+) -Nd~(3+)-Yb~(3+) codoped CaTiO_3 perovskite phosphors synthesized via solid state reaction technique under 808 nm and 980 nm co-excitation has been described. The band gap analysis and Rietveld refinement has been done on the basis of UV-Vis and XRD spectra. Frequency upconversion observed in the developed phosphors has been explained with the help of steady rate equations. Fluorescence intensity ratio (FIR) based temperature sensing study of the developed phosphors for different combination of thermally coupled Stark levels under co-excitation has been analysed over a range of 303-573 K. Consequently, the maximum sensitivity ～10.9 × 10~(-3) K~(-1) at room temperature (303 K) with an excellent thermal resolution (～0.4 K) due to Stark splitting thermally coupled (~2H_(11/(2(1))) & ~4S_(3/(2(2)))) levels in comparison to the conventional ~2H_(11/2) & ~4S_(3/2) levels has been reported.