A novel Mn2+ doped ScTaO4 dual-emitting phosphor for high temperature optical thermometry

Abstract

A novel Mn²⁺ doped ScTaO₄ phosphor was synthesized through a high temperature solid state method and its photoluminescence properties were systematically investigated. The ScTaO₄:Mn²⁺ phosphor exhibited two emission bands centered at 478 nm and 661 nm under UV excitation, attributed to the self-activated emission of the host and the ⁴T₁ → ⁶A₁ transition emission from doped Mn²⁺ ions, respectively. Through optimizing the concentration of doped Mn²⁺ ions, white light emission was achieved. Meanwhile, the temperature-dependent luminescence spectra of the ScTaO₄:Mn²⁺ phosphor (in the range from 298 K to 523 K) revealed significantly different thermal quenching behaviors between the host and Mn²⁺ ions, which cause a notable change in the fluorescence intensity ratio of the host versus Mn²⁺ ions and enable high absolute and relative sensitivities, with maximum values of 0.0172 K⁻¹ and 2.1% K⁻¹ at 523 K, respectively. The results indicated that the as-prepared STO:Mn²⁺ phosphor can be a potential candidate material for high temperature optical thermometry.