A Wide-Range Dual-Mode Fluorescence Thermometry Based on RE3+-Doped Negative Thermal Expansion Bimetallic Perovskite With Anti-Thermal Quenching Luminescence Properties

Non-contact luminescence thermometry featuring high resolution and high sensitivity represents a crucial application of lanthanide upconversion materials. Nevertheless, primarily due to the thermal quenching (TQ) effect, traditional fluorides continue to present significant challenges in attaining real-time, high-sensitivity temperature sensing across a broad temperature spectrum. In this study, two thermometers are developed based on the thermal coupling energy levels (TCLs) and non-thermal coupling energy levels (NTCLs) of CaZrF 6 :3%Yb; 2%Er. Benefiting from the luminescence thermal enhancement induced by lattice thermal contraction, these ratio-type thermometers demonstrate the ability to operate within an extensive temperature range, spanning from relatively low to high temperatures (193 ∼ 793 K). TCLs and NTCLs display extraordinarily comparatively large relative sensitivity of 1.53 and 1.45% K −1 at room temperature. Most notably, based on NTCLs, the absolute sensitivity value consistently remains above 4.00 × 10 − 2 K −1 within the high-temperature range (393–793 K), and attains a maximum of 5.08 × 10 − 2 K −1 at 543 K, which is significantly higher than those of the vast majority of Yb 3+ /Er 3+ -doped optical temperature-measurement materials. These results offer a novel approach for the advancement of high-sensitivity and high-resolution sensor devices across a wide temperature range (Especially in high-temperature).