Low-doped LaVO₄:Eu³⁺ phosphor for multimode optical thermal sensing

In the last decade much attention has been paid to the development of novel approaches in luminescence thermometry, which could allow contactless and noninvasive temperature sensing when traditional thermometers are useless. Typically, an optical thermometer exploits a distinct luminescence parameter to define temperature. However, the use of multimode sensors can significantly broaden the working range and improve the reliability of the temperature measurements. In this work, a Eu³⁺-doped LaVO₄ sample was successfully utilized as a thermal sensor within a wide temperature range of 98-723 K based on monitoring various temperature-sensitive luminescence features. Different thermal sensing strategies were assessed and compared in terms of thermal sensitivity and temperature resolution. The best thermometric performances of the Eu³⁺-doped LaVO₄ sensor reached an S_r = 1.49% K^-1 and a ΔT = 0.6 K at room temperature. All the studies performed showed that the LaVO₄:Eu³⁺ phosphor is a prospective multimode optical thermometer.