Multiparametric luminescence thermometry from Dy3+, Cr3+ double activated YAG

The multiparametric luminescence thermometry with Dy3+, Cr3+ double activated yttrium aluminium garnet – YAG is demonstrated. Phospors were synthesized via Pechini method and their structure is confirmed by X-ray diffraction analysis. Mean crystallite size of powders was calculated to be ~22 nm. Morphology was investigated using scanning electron microscopy showing combination of dense, different size chunks constituted of spherical particles bellow 50 nm in size. Photoluminescence emission spectra of the Dy3+, Cr3+ double activated YAG consist of blue and yellow Dy3+ emissions and the broad, deep red Cr3+ emission. The decrease in the Dy3+ emission intensity with the increase in the Cr3+ content indicates the efficient energy transfer from Dy3+ to Cr3+ of ~90%. Temperature-dependant photoluminescence emission measurements are performed under 484 nm and 582 nm excitation in the steady-state domain and in the 175 K–650 K temperature range. The noted alterations of luminescence with temperature present an excellent base for studying the multiparametric temperature readouts. The luminescence intensity ratio, the most frequently exploited luminescent thermometry temperature readout method, was tested using: i) the combination of Dy3+ and Cr3+ emissions, ii) using the double excitation approach, and iii) using Cr3+ emission only, with relative sensitivities of 0.64 %K−1 at 175 K, 0.96 %K−1 at 200 K and 2.2 %K−1 at 200 K, respectively.