Ratiometric Optical Thermometry Based on Emission and Excitation Spectra of YVO4:Eu3+ Nanophosphors

Development of new approaches to the noncontact optical thermometry is of great importance for modern science and technology. In the current work, single-phase YVO4:Eu3+ nanoparticles prepared via the modified Pechini technique were studied as luminescence thermometers. Thermal sensing was performed using two different ratiometric approaches: utilizing the luminescence intensity ratio between transitions emitted from two thermally coupled excited levels (emission spectrum) and between transitions originating from different thermally coupled low-lying levels (excitation spectrum). The first technique allows determining temperature within the 298–873 K range, whereas the second one allows determining temperature within 298–473 K. The spectral position of the 5D0(1)–7F1(2) band was also suggested as a temperature-dependent parameter. Thermometric performance of YVO4:Eu3+ nanophosphors including absolute and relative sensitivities, minimum temperature uncertainty, and repeatability was obtained and discussed.