A novel Tb3+ and Eu3+ co-doped dual-emitting phosphate K3SrBi(P2O7)2 phosphor for application in FIR thermometers

Rare earth co-doped phosphor for fluorescence intensity ratio (FIR) thermometer has gained increasing attention in recent years. Herein, the novel Tb3+ and Eu3+ co-doped K3SrBi(P2O7)2 (KSBP) phosphate phosphors were reported. The crystal structure of the title phosphor was determined using Rietveld refinement and proved to have a three-dimensional structure. The time-resolved spectroscopy reveals that there is almost no energy transfer between Tb3+ and Eu3+. More importantly, Tb3+ and Eu3+ emissions show different thermal quenching behaviors, which claims the potential of this material for application in optical thermometer. The FIR of the typical KSBP:0.02Tb3+,0.04Eu3+ sample demonstrates a polynomial relationship as a function of temperature and the absolute and relative sensitivity are 0.025 K–1 and 0.59%/K, respectively. In general, our study reports a novel and potential KSBP:Tb3+,Eu3+ phosphate phosphor that is promising for use in high-sensitive FIR thermometers.