Luminescent Platform for Thermal Sensing and Imaging Based on Structural Phase‐Transition
Anam Javaid, Maja Szymczak, Malgorzata Kubicka, Vasyl Kinzhybalo, M. Drozd, Damian Szymański, Ł. Marciniak
Abstract
Abstract The luminescent properties of Eu 3+ ions are highly sensitive to changes in their local crystal environment. While this feature has been widely studied, its application in thermometers based on thermally induced structural phase transitions is a recent development. These thermometers often suffer from a narrow thermal operating range, prompting the search for new host materials. In this context, Na 3 Sc 2 (PO 4 ) 3 :Eu 3+ as a function of temperature and dopant ion concentration. As demonstrated, Na 3 Sc 2 (PO 4 ) 3 :Eu 3+ was investigated as a potential candidate. This material undergoes a reversible phase transition from a monoclinic to a trigonal structure, leading to significant changes in both the emission spectra and the luminescence decay of Eu 3+ ions. These effects enable the development of both ratiometric and lifetime‐based luminescent thermometers, achieving maximum relative sensitivities of 3.4% K −1 and 1.0% K − 1, respectively. Furthermore, the thermal operating range can be tuned by adjusting the Eu 3+ concentration. Importantly, this study demonstrates, for the first time, temperature imaging using only Eu 3+ ‐doped phosphor via a digital camera without the use of optical filters. These results position Na 3 Sc 2 (PO 4 ) 3 :Eu 3+ as a promising multifunctional material for advanced applications in contactless temperature sensing and thermal imaging.