Enhancing the Relative Sensitivity of V(5+), V(4+) and V(3+) Based Luminescent Thermometer by the Optimization of the Stoichiometry of Y(3)Al(5−x)Ga(x)O(12) Nanocrystals

In this work the influence of the Ga(3+) concentration on the luminescent properties and the abilities of the Y(3)Al(5−x)Ga(x)O(12): V nanocrystals to noncontact temperature sensing were investigated. It was shown that the increase of the Ga(3+) amount enables enhancement of V(4+) emission intensity in respect to the V(3+) and V(5+) and thus modify the color of emission. The introduction of Ga(3+) ions provides the appearance of the crystallographic sites, suitable for V(4+) occupation. Consequently, the increase of V(4+) amount facilitates V(5+) → V(4+) interionic energy transfer throughout the shortening of the distance between interacting ions. The opposite thermal dependence of V(4+) and V(5+) emission intensities enables to create the bandshape luminescent thermometr of the highest relative sensitivity of V-based luminescent thermometers reported up to date (S(max), 2.64%/°C, for Y(3)Al(2)Ga(3)O(12) at 0 °C). An approach of tuning the performance of Y(3)Al(5−x)Ga(x)O(12): V nanocrystals to luminescent temperature sensing, including the spectral response, maximal relative sensitivity and usable temperature range, by the Ga(3+) doping was presented and discussed.