Dual-mode green emission and temperature sensing properties of rare-earth-element-doped biphasic calcium phosphate composites

This work presents a novel multifunctional material synthesized by hydroxyapatite/beta-tricalcium phosphate (HA/beta-TCP) doped with Er-Yb-Mo ions (using hydrothermal method) and its characterization, showing a peculiar property of green dual-mode emissions (up and down-conversions). It was found that the obtained material exhibits an intense green emission (510-560 nm) both via up-conversion (excited by 975 nm) and down-conversion (excited by 379 nm), which depend on the Mo6+ contents. Particularly, compared with the free-Mo6+ sample, the green emission intensities of the samples doped with 5% Mo6+ mol are 50 and 35 times higher for UC and DC emissions, respectively. Furthermore, the temperature sensing property of the HA/beta-TCP: Er-Yb-Mo composite is investigated by fluorescence intensity ratio (FIR) technique, showing a high and competitive sensitivity with a maximum value of 0.0064 K-1 at 403 K. The results indicated that the HA/beta-TCP: Er-Yb-Mo phosphor can be useful for high-temperature-sensing applications. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This research introduces a novel multifunctional material synthesized by doping Er-Yb-Mo ions into hydroxyapatite/beta-tricalcium phosphate using the hydrothermal method, demonstrating a unique green dual-mode emissions property. The material shows intense green emission through both up-conversion and down-conversion processes, with emission intensity depending on the Mo6+ content, making it potentially useful for high-temperature sensing applications.