The study on optical temperature measurement based on ESA and GSA design using abnormal thermal quenching behavior

Luminescence Intensity Ratio (LIR) temperature measurement in optical thermometry offers advantages, such as high sensitivity and accuracy, wide temperature range measurement, and fast response, making it have broad application prospects. Meanwhile, negative thermal quenching characteristics have gradually shown their importance and potential in the field of optical thermometry. In this study, a phosphor, Sc2Mo3O12:Sm3+, was designed based on ground-state absorption and first excited-state absorption for LIR temperature sensing, exhibiting anomalous thermal quenching behavior. According to in situ XRD analysis, the role of negative thermal expansion characteristics in crystal repair and charge transfer state coordinate shifts is revealed, which leads to the anomalous thermal quenching behavior of Sm3+ ions. The LIR temperature sensing of this phosphor demonstrates high Sr, Sa, and δT values (Sr = 2.66% K−1, Sa = 8.07% K−1, and δT = 0.02 K−1). Finally, we embed this phosphor into polydimethylsiloxane to fabricate a flexible film, enabling real-time and accurate temperature measurement in daily life.