Structural, luminescence and thermometric properties of nanocrystalline YVO₄:Dy³⁺ temperature and concentration...

We report systematic study of Dy³⁺-doped YVO₄ nanophosphors synthesized via modified Pechini technique. Effect of calcination temperature and doping concentration on structure and luminescence has been investigated. XRD and Raman spectroscopy revealed preparation of single phase nanoparticles without any impurities. Synthesized nanopowders consisted of weakly agglomerated nanoparticles with average size about 50 nm. Photoluminescence spectra of YVO₄:Dy³⁺ nanoparticles consisted of the characteristic narrow lines attributed to the intra-configurational 4f-4f transitions dominating by the hypersensitive ⁴F_9/2-⁶H_13/2 transition. The calcination temperature variation did not affect ⁴F_9/2 lifetime, whereas increase of doping concentration resulted in its gradual decline. Potential application of YVO₄:Dy³⁺ 1 at.% and 2 at.% nanopowders as ratiometric luminescence thermometers within 298-673 K temperature range was tested. The main performances of thermometer including absolute and relative thermal sensitivities and temperature uncertainty were calculated. The maximum relative thermal sensitivity was determined to be 1.8% K^-1@298 K, whereas the minimum temperature uncertainty was 2 K.