Luminescent properties and fluorescence intensity ratio-based optical thermometry of Dy3+/Eu3+ co-activated oxyfluoride glass–ceramics

This study delves into the luminescent properties and fluorescence intensity ratio (FIR)-based optical thermometry of Dy3+/Eu3+ co-activated oxyfluoride glass-ceramics. The research focuses on the energy transfer mechanisms between Dy3+ and Eu3+ ions, highlighting the significant spectral overlap that facilitates efficient energy transfer. The investigation includes the synthesis and characterization of K3YF6 nanocrystals, with a detailed analysis of their crystal structure, optical transmission properties, and photoluminescence spectra. The study also explores the temperature-dependent emission spectra and the thermal stability of the materials, demonstrating their potential for non-contact optical temperature measurement. The results indicate that the Dy3+/Eu3+ co-doped K3YF6 glass-ceramics exhibit excellent color tunability and high thermal stability, making them suitable for applications in warm white lighting devices and optical thermometers. The dual-mode sensing strategy, which exploits both intra-ionic thermal coupling in Dy3+ and inter-ionic energy transfer to Eu3+, enables accurate and wide-range temperature detection with high stability and reliability.