Sensitive multimode luminescence thermometry through CaZnOS:Pb2+/Mn2+ microcrystals

Developing advanced luminescent thermometers that offer various thermometry modes is essential for remote temperature measurement with high precision. In this study, a novel tri-mode optical thermometer was designed using Pb 2+ and Mn 2+ co-doped CaZnOS microcrystals. The structure, luminescence properties, energy transfer (ET) mechanism, and temperature sensing performance were comprehensively investigated. Dual emission of Pb 2+ and Mn 2+ was achieved by excitation at 290 or 358 nm. Additionally, ET from Pb 2+ to Mn 2+ was demonstrated in the CaZnOS host. Based on excellent temperature-dependent optical properties, parameters including luminescence intensity ratio (LIR), coordinates of Commission Internationale de L'Eclairage (CIE), and excitation intensity ratio (EIR) were developed for temperature sensing. The maximum relative sensitivity ( S r ) is 2.92% K −1 (303 K) through LIR mode, 0.562% K −1 (324 K) through CIE mode, and 0.879% K −1 (303 K) through EIR mode, respectively. The excellent thermometric performance indicates the rationally designed material has great potential in multimode optical thermometry. • A novel tri-mode (LIR, CIE, and EIR) optical thermometer was designed using Pb 2+ and Mn 2+ co-doped CaZnOS microcrystals. • Dual emission of Pb 2+ and Mn 2+ was achieved by dual excitation at 290 nm or 358 nm. • Host-to-dopants and Pb 2+ -to-Mn 2+ energy transfer were identified and investigated as a function of temperature. • A flexible thin-film temperature indicator was developed by combining the CaZnOS:Pb 2+ /Mn 2+ phosphors with PDMS for detecting the real-time temperature of objects.