Thermally boosted upconversion and downshifting luminescence in Sc<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub>:Yb/Er with two-dimensional negative thermal expansion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35440128.
- Also identified by DOI 10.1038/s41467-022-29784-6 and PMC identifier 9019035.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Rare earth (RE<sup>3+</sup>)-doped phosphors generally suffer from thermal quenching, in which their photoluminescence (PL) intensities decrease at high temperatures. Herein, we report a class of unique two-dimensional negative-thermal-expansion phosphor of Sc<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub>:Yb/Er. By virtue of the reduced distances between sensitizers and emitters as well as confined energy migration with increasing the temperature, a 45-fold enhancement of green upconversion (UC) luminescence and a 450-fold enhancement of near-infrared downshifting (DS) luminescence of Er<sup>3+</sup> are achieved upon raising the temperature from 298 to 773 K. The thermally boosted UC and DS luminescence mechanism is systematically investigated through in situ temperature-dependent Raman spectroscopy, synchrotron X-ray diffraction and PL dynamics. Moreover, the luminescence lifetime of <sup>4</sup>I<sub>13/2</sub> of Er<sup>3+</sup> in Sc<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub>:Yb/Er displays a strong temperature dependence, enabling luminescence thermometry with the highest relative sensitivity of 12.3%/K at 298 K and low temperature uncertainty of 0.11 K at 623 K. These findings may gain a vital insight into the design of negative-thermal-expansion RE<sup>3+</sup>-doped phosphors for versatile applications.