Design and analysis of PiG-based ratiometric thermometer integrating positive and negative thermal quenching materials

Abstract

In this study, a novel optical thermometer based on a phosphor-in-glass (PiG) composite was designed, incorporating 9 mol% Nd³⁺:Yb₂W₃O₁₂ and 0.5 mol% Ho³⁺:Yb₂W₃O₁₂ phosphors into a silicate glass matrix. Upon excitation at 980 nm, the 9 mol% Nd³⁺:Yb₂W₃O₁₂ phosphor exhibited a thermal enhancement in the near-infrared anti-Stokes emissions of Nd³⁺ with an increase in temperature, whereas the up-conversion luminescence of Ho³⁺ in the 0.5 mol% Ho³⁺:Yb₂W₃O₁₂ phosphor decreased. Utilizing the luminescence intensity ratio of Nd³⁺ to Ho³⁺ (I_{720–920 nm}/I_{520–580 nm}), a maximal relative sensing sensitivity of approximately 4.86 %K⁻¹ was achieved. Moreover, the glass matrix effectively prevented the invasion of water molecules, thereby mitigating the deleterious effects of the hygroscopicity of Yb₂W₃O₁₂. This work provides useful information for developing novel high-performance ratiometric luminescence thermometers.