Temperature Sensing Performance of ScVO ₄: Eu ³⁺ Phosphors by Employing Ground State Thermal Coupling Approach

Abstract

Lanthanides doped vanadate luminescence materials have gained a lot of attention for their use in non-contact optical thermometry, because of the advantages of non-intrusive and real-time temperature detection. The approach of fluorescence intensity ratio (FIR) of two thermally coupled excited states is the most promising approach but their performance in a lower temperature range is limited due to thermal decoupling among the two emitting levels with a wide energy gap. Thus, in this work, the temperature sensing ability of ScVO₄:2% Eu³⁺ phosphor synthesized successfully through a high-temperature solid-state reaction has been explored by employing the ground state thermal coupling approach. Various experimental and theoretical approaches were used to check the structure and compositional stability of the synthesized ScVO₄:2%Eu³⁺ phosphors host lattice. The temperature-dependent emission intensity of ⁵D₀→⁷F₄ has been measured under 616.3 nm excitation corresponding to ⁵D₀→⁷F₂ absorption, which shows the remarkable increasing behavior with rising of temperature ranging from 113 K to 323 K. The highest value of the relative sensitivity reached 7.19% K^-1 at 113 K which is higher than previously reported materials. The obtained results reveal that ScVO₄:2% Eu³⁺ phosphor is a promising candidate for non-contact optical thermometry.

Keywords: ScVO4:2% Eu3+, Non-Contact Optical Thermometry, Ground State Thermal Coupling, Relative Sensitivity