Enhancing sensitivity and detection range of Ca2GdZr2Al3O12:Bi3+,Tb3+ fluorescent thermometer via multi-excitation pathways and anti-thermal quenching

A series of Ca 2 Gd 1-x-y Zr 2 Al 3 O 12 :xBi 3+ ,yTb 3+ phosphors have been successfully synthesized. • The anti-thermal quenching behavior of Tb 3+ ions was attributed to the synergistic effect of electron-phonon coupling and crystal field. • A dual-pathway FIR thermometer has been developed that achieves high sensitivity over a broad temperature range. • Optical materials were fabricated for optical fiber temperature detection platform and anti-counterfeiting label. Developing fluorescence intensity ratio (FIR) thermometers with low cost, high sensitivity and wide measurement range is a key bottleneck in this field, which poses severe challenges to conventional thermosensitive materials. Herein, a series of Ca 2 GdZr 2 Al 3 O 12 :Bi 3+ ,Tb 3+ phosphors with multi-excitation pathways were fabricated, and anti-thermal quenching (ATQ) behavior was attributed to the synergistic effect of electron-phonon coupling and crystal field, boosting the sensitivity and temperature detection range of fluorescent thermometers. Among them, under the excitation pathway where both Bi 3+ and Tb 3+ ions exhibit typical TQ behaviors, the FIR 309 thermometer achieves a maximum S r 309 value of 1.46% K −1 (at 353 K), thereby exhibiting excellent temperature sensing performance in the range of 293–433 K. In contrast, for the excitation pathway where the ATQ behavior of Tb 3+ ions is realized via the synergistic effect of electron-phonon coupling and crystal field, the S r 322 value of the FIR 322 optical thermometer increases to 2.05% K −1 , and shifts the high-sensitivity detection range to 413–573 K. Notably, the combined temperature detection range (293–573 K) of the FIR 309 and FIR 322 thermometers is two times that of the single FIR 309 thermometer. Moreover, the multi-pathway FIR optical thermometer exhibits outstanding temperature measurement performance on the optical fiber temperature detection platform. These promising findings offers a new perspective for developing optical thermometer with exceptional performance. Download: Download high-res image (85KB) Download: Download full-size image