A new luminescent material LaTiSbO6:Mn4+/Er3+ with high optical temperature sensing sensitivity based on fluorescence intensity ratio

Abstract

In recent years, the development of Er³⁺-doped phosphors for temperature sensing using the fluorescence intensity ratio (FIR) of the thermally coupled energy levels (²H_11/2 and ⁴S_3/2) of Er³⁺ has become a popular research topic, often limited by relatively low sensitivities. In this study, a new type of Mn⁴⁺/Er³⁺ co-doped phosphor, LaTiSbO₆:Mn⁴⁺/Er³⁺ (LTS:Mn⁴⁺/Er³⁺), was designed by utilizing the thermal enhancement characteristics of Er's ²H_11/2 → ⁴I_15/2 emission peak and the rapid thermal quenching of Mn's ²E_g → ⁴A_2g emission peak. It was found that it showed a significant improvement in temperature sensitivity precision compared to the Er³⁺ single-doped phosphor LTS:Er³⁺ (nearly 4.6-fold), with a relative sensitivity of 5.100% K⁻¹. Additionally, we investigated the temperature sensing properties based on the second model of fluorescence lifetime for this phosphor. The achievement of this work lies not only in reporting a new phosphor for temperature sensing but also in providing a design idea for future research in this field.