Influence of the Synthesis Conditions on the Morphology and Thermometric Properties of the Lifetime-Based Luminescent Thermometers in YPO4:Yb3+,Nd3+ Nanocrystals

The role of Nd3+ concentration in the modulation of the thermometric performance of Stokes/anti-Stokes luminescence thermometer in NaYF4:Nd3

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 (⁴F_3/2 → ⁴I_9/2) to anti-Stokes (⁴F_7/2,⁴S_3/2 → ⁴I_9/2) emission intensities in NaYF₄:Nd³⁺. It is shown that the spectral broadening of the ⁴I_9/2 → ⁴F_5/2, ²H_9/2 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.