Dy3+,Eu3+ co-doped double perovskite Ca2GdNbO6 phosphors for fluorescent thermometer

Fluorescent thermometers based on lanthanide-doped phosphors have broad application prospect because of their quickly response, highly sensitivity, non-contact mode and widely application scenarios. However, their relative sensitivity is limited by fixed thermal coupling energy level. Herein, Ca 2 GdNbO 6 :Dy 3+ ,Eu 3+ samples possessing dual-emission centers were fabricated as fluorescence thermometers based non-thermal coupling energy level. When excited by 393.5 nm, the characteristic emissions from Dy 3+ and Eu 3+ in CGNO:Dy 3+ ,Eu 3+ can be simultaneously detected. Furthermore, CGNO:Dy 3+ ,Eu 3+ phosphors exhibit excellent temperature sensing performance in fluorescence intensity (FI) relied on Eu 3+ and fluorescence intensity ratio (FIR) relied on dual-emission centers. The maximum relative sensitivities ( S Rmax ) reach 1.61 %K −1 at 426 K for FI at 703 nm, 1.01 %K −1 at 391 K for FIR of FI at 616 nm and FI at 576 nm, and 2.18 %K −1 at 501 K for FIR of FI at 703 nm and FI at 576 nm, respectively. These findings demonstrate that Ca 2 GdNbO 6 :Dy 3+ ,Eu 3+ samples are prime candidates for fluorescent thermometers.