Impact of Noise and Background on Measurement Uncertainties in Luminescence Thermometry

Abstract

Materials with temperature-dependent luminescence can be used as local thermometers when incorporated in, for example, a biological environment or chemical reactor. Researchers have continuously developed new materials aiming for the highest sensitivity of luminescence to temperature. Although the comparison of luminescent materials based on their temperature sensitivity is convenient, this parameter gives an incomplete description of the potential performance of the materials in applications. Here, we demonstrate how the precision of a temperature measurement with luminescent nanocrystals depends not only on the temperature sensitivity of the nanocrystals but also on their luminescence strength compared to measurement noise and background signal. After first determining the noise characteristics of our instrumentation, we show how the uncertainty of a temperature measurement can be predicted quantitatively. Our predictions match the temperature uncertainties that we extract from repeated measurements, over a wide temperature range (303–473 K), for different CCD readout settings, and for different background levels. The work presented here is the first study that incorporates all of these practical issues to accurately calculate the uncertainty of luminescent nanothermometers. This method will be important for the optimization and development of luminescent nanothermometers.

How to calibrate luminescent crossover thermometers: a note on “quasi”-Boltzmann systems

“…It should be noted, however, that it is the interplay between the relative sensitivity and high signal-to-noise ratio that defines the practically actually relevant quantity of statistical precision of a luminescent thermometer. 13,58,59 The statistically expected relative temperature uncertainty is given bywith R 21 ( T ) and S r ( T ) as given in eqn (4) and (5), respectively. Formula (6) is valid under the assumption of Poissonian photon counting statistics of the photodetector, which is given for a photomultiplier.…”

“…It should be noted, however, that it is the interplay between the relative sensitivity and high signal-tonoise ratio that defines the practically actually relevant quantity of statistical precision of a luminescent thermometer. 13,58,59 The statistically expected relative temperature uncertainty is given by…”

Less is more: dimensionality reduction as a general strategy for more precise luminescence thermometry

“…Moreover, photon extinction by biological tissues strongly reduces both the number of excitation photons reaching the luminescent probe (nanoparticle) and the number of emitted photons collected by the detection systems 41 . Swieten et al have demonstrated that when working in conditions of low signal-to-noise ratio, the thermal uncertainty is affected and the performance of the thermometer is compromised 42 . It is therefore desirable to improve the quality of the thermal readout in such circumstances.…”

Dual-emission luminescence thermometry using LaGaO3:Cr3+, Nd3+ phosphors

“…The reason behind the low uncertainties in temperature measurements using this probe is that both emissions utilised for LIR have high intensities. Swieten et al 60 recently demonstrated that signal strength is directly proportional to the precision of the temperature measurement. As already mentioned, Cr 3+ emission in the strong crystal field is comprised of the 4 T 2 and 2 E bands, with opposite trends with change in temperature.…”

“…Swieten at al. 45 recently demonstrated that signal strength is directly proportional to the precision of the temperature measurement. As already mentioned, Cr 3+ emission in the strong crystal field is comprised of the 4 T2 and 2 E bands, with opposite trends with change in temperature.…”