Glowing performance for a luminescence thermometry technique
Glowing performance for a luminescence thermometry technique lead image
Luminescence thermometry is a method for determining temperature that measures the light emitted by a probe. Based on the (often fiber-optic) glowing probe, it is possible to extract temperature information independent of environmental factors that burden other temperature reading techniques like traditional temperature sensors or infrared cameras. This makes it ideal for many biomedical and industrial applications.
However, the common luminescence approach relies on comparing the rates of temperature change for two emission peaks, called the Luminescence Intensity Ratio (LIR), which fails at the high temperatures many of its applications operate at.
Ćirić et al. filled this measurement gap with the Luminescence Intensity Ratio Squared (LIR2) that enables high-precision luminescent thermometry for temperatures ranging from a few hundred to over a thousand degrees Kelvin.
“LIR precision depends not only on sensitivity but also on the intensity of emission and uncertainty in that measurement,” said author Aleksandar Ćirić. “LIR measurements are often observed emissions from two emissive levels of a single ion, which are said to be thermalized as the ratio of emission intensities depends on the Boltzmann distribution.”
LIR is easy and effective at lower temperatures, but in industrial or biological applications LIR2 provides higher sensitivity by using two thermalizations.
In the visible region, the sensitivity of LIR2 outperforms LIR by 70%. For near-infrared regions of the spectrum, where biological samples often fall, LIR2 proved 230% more sensitive. The authors also found that LIR2 doubled the precision for temperatures ranging over a thousand degrees Kelvin.
They hope that expanding the potential applications will encourage more work in luminescence thermometry, especially in developing higher-sensitivity probes.
Source: “Twofold increase in sensitivity of Er3+/Yb3+ Boltzmann thermometer,” by Aleksandar Ćirić, Thomas van Swieten, Jovana Periša, Andries Meijerink, and Miroslav D. Dramicanin, Journal of Applied Physics (2023). The article can be accessed at https://doi.org/10.1063/5.0149757 .
