A novel dichromic self-referencing optical probe SrO:Bi3+,Eu3+ for temperature spatially and temporally imaging

Abstract

A novel dichromic luminescence probe SrO:Eu³⁺,Bi³⁺ for temperature sensing is achieved. The detailed luminescence properties, e.g., the excitation emission spectra, energy transfer efficiency, luminescence decay lifetimes and temperature dependent luminescence are comprehensively studied. The two dominant emissions ⁵D₀ → ⁷F₂ transition of Eu³⁺ and the ³P₁ → ¹S₀ transition of Bi³⁺ display adjustable spectrum area. The interaction effect between Eu³⁺ and Bi³⁺ are proposed. The dichromic emissions are specifically responding to temperature with high sensitivity at ultra-wide range from 30 to 400 °C. Spatial and temporal temperature images on an aircraft surface have been successfully realized under excitation of commercial 365 nm light emitting diode (LED) by painting the SrO:Bi³⁺,Eu³⁺ phosphor on a plane model. Finally, the thermal quenching mechanism revealed by Arrhenius theory is employed to interpret the temperature sensitive luminescence behaviour.