Eu<sup>3+</sup>-based dual-excitation single-emission luminescent ratiometric thermometry
Yuanbo Yang, Leipeng Li, Hao Suo, Panlai Li, Zhijun Wang, Zhiguo Zhang
Abstract
Recently, single-band ratiometric (SBR) thermometry becomes a hot-spot in the research field of optical thermometry. Here we propose a new SBR thermometry by combining the temperature-induced red shift of charge transfer state (CTS) of W-O and Eu-O with the ground state absorption (GSA) and excited state absorption (ESA) of Eu 3+ . The emitting intensity of the 5 D 0 - 7 F 2 transition of Eu 3+ is monitored under CTS, GSA and ESA excitations at different temperatures. It is found that the SBR thermometry, depending on the combination of [GSA + CTS] of Eu 3+ doped calcium tungstate, has the highest relative sensitivity of 1.25% K −1 at 573 K, higher than conventional luminescent ratiometric thermometry such as the 2 H 11/2 and 4 S 3/2 thermally coupled states of Er 3+ .