A new generation of dual-mode optical thermometry based on ZrO ₂ :Eu ³⁺ nanocrystals

Abstract

Abstract For achieving well-performing optical thermometry, a new type of dual-mode optical thermometer is explored based on the valley-to-peak ratio (VPR) and fluorescence lifetime of Eu 3+ emissions in the ZrO 2 :Eu 3+ nanocrystals with sizes down to 10 nm. In the VPR strategy, the intensity ratio between the valley (600 nm) generated by the emission band overlap and the 606 nm peak ( 5 D 0 → 7 F 2 ), which is highly temperature sensitive, is employed, giving the maximum relative sensing sensitivity ( S r ) of 1.8% K −1 at 293 K and good anti-interference performance. Meanwhile, the 606 nm emission exhibits a temperature-dependent decay lifetime with the highest S r of 0.33% K −1 at 573 K, which is due to the promoted nonradiative relaxation with temperature. These results provide useful information for constructing high-performance dual-mode optical thermometers, which may further stimulate the development of photosensitive nanomaterials for frontier applications.