Multi‐mode temperature sensing of Lu₂WO₆:Er³⁺,Yb³⁺ up‐conversion materials

To develop multi‐mode fluorescence thermometer with high performance, Lu 2 WO 6 :Er 3+ ,Yb 3+ materials were successfully designed and prepared. Under 980 nm excitation, the material can achieve accurate temperature measurement under three models. The above three models are based on different parameters, including two FIR (fluorescence intensity ratio) derived from two thermally coupled energy levels (TCELs) ( 2 H 11/2 / 4 S 3/2 ) and two non‐thermally coupled energy levels (NTCELs) ( 2 H 11/2 / 4 F 9/2 ), as well as fluorescence lifetime (FL) monitoring of the 2 H 11/2 energy level transition to the ground state. In the FIR mode of TCELs, maximum relative sensitivity ( S R‐max ) and minimum temperature resolution are 1.261 %K –1 and 0.237 K, respectively. The repeatability of five‐cycle temperature measurements is above 98.5%. The S R‐max value of FIR (NTCELs) and FL mode reach 0.862 and 0.201 %K −1 , respectively. The obtained outcomes suggest that Lu 2 WO 6 :Er 3+ ,Yb 3+ materials might be considered as promising candidates for three‐mode fluorescence thermometry.