K. Maciejewska & L. Marciniak
Published: 10 January 2023
The growing popularity of luminescence thermometry observed in recent years is related to the high application potential of this technique. However, in order to use such materials in a real application, it is necessary to have a thorough understanding of the processes responsible for thermal changes in the shape of the emission spectrum of luminophores. In this work, we explain how the concentration of Nd3+ dopant ions affects the change in the thermometric parameters of a thermometer based on the ratio of Stokes (4F3/2 → 4I9/2) to anti-Stokes (4F7/2,4S3/2 → 4I9/2) emission intensities in NaYF4:Nd3+. It is shown that the spectral broadening of the 4I9/2 → 4F5/2, 2H9/2 absorption band observed for higher dopant ion concentrations enables the modulation of the relative sensitivity, usable temperature range, and uncertainty of temperature determination of such a luminescent thermometer.
The anti-Stokes (a); and Stokes (b) parts of emission of NaYF4:1%Nd3+ nanoparticles upon 808 nm excitation; the impact of the concentration of Nd3+ ions on thermal evolution of normalized integral emission intensities of 4F3/2 → 4I9/2 (c) and 4F7/2,4S3/2 → 4I9/2 (d) emission bands of NaYF4: Nd3+ nanoparticles; the temperature dependent LIR values of NaYF4:Nd3+ nanoparticles (e); the corresponding SR (f).