High-sensitivity based on Eu2+/Cr3+ co-doped BaAl12O19 phosphors for dual-mode optical thermometry

Abstract A series of Eu2+/Cr3+ co-doped BaAl12O19 phosphor was synthesized by traditional high temperature solid stated method, and the temperature-sensitive characteristic of the phosphor was researched. Due to the temperature sensitivity of the fluorescence lifetime of Cr3+, the thermometry based on fluorescence lifetime can be realized. Furthermore, the emissions of Eu2+ ion and Cr3+ ion can be well separated, which shows the excellent signal recognition ability of this phosphor. The Eu2+/Cr3+ co-doped BaAl12O19 phosphor can be used for the thermometry based on fluorescence intensity ratio. A dual-mode optical thermometry is proposed and researched in the temperature range of 293–563 K by using the decay lifetime of Cr3+ emission and in the temperature range of 295–476 K by using the fluorescence intensity ratio of Eu2+ to Cr3+as temperature readout. The maximum values of relative sensitivity are 0.466% K−1 at 363 K and 0.259% K−1 at 476 K. The Eu2+/Cr3+ co-doped BaAl12O19 phosphor has excellent optical temperature characteristic, and its dual-mode thermometry characteristics provide convenience for the application of this material. This phosphor has potential application prospects in the field of optical thermometry.