“…However, these methods require the physical contact with the object and cannot be used in a corrosive environment or organism. To overcome this issue, numerous types of luminescent thermometers, made up of quantum dots, polymer-based systems, organic dyes, and lanthanide ion (Ln 3+ )-doped materials, have been investigated (Feng et al, 2011;Vlaskin et al, 2010;Yan et al, 2010;Jia et al, 2020). Among these luminescent thermometers, Ln 3+ -doped up-conversion materials have drawn extensive attention in the research of non-invasive temperature measurement due to their fast response, high resolution, low toxicity, remote detection, and so on (Labrador-Páez et al, 2018;Ximendes et al, 2016;Skripka et al, 2017;Nexha et al, 2021).…”