Luminescence and temperature sensing properties of Bi3+/Mn4+ doped double-perovskite BaSrGdSbO6 phosphors

Bi 3+ /Mn 4+ co-doped BaSrGdSbO 6 phosphors show dual emissions under 330 nm excitation. • Distinct thermal responses of Bi 3+ and Mn 4+ enable ratio-type optical thermometry. • A maximum relative sensitivity of 2.02% K −1 is achieved at 473 K. The temperature measurement technology based on the fluorescence intensity ratio has garnered significant attention due to its high accuracy, rapid response, and non-contact advantages. Herein, novel double-perovskite BaSrGdSbO 6 : Bi 3+ /Mn 4+ phosphors were synthesized and their luminescence properties were investigated in detail. Under 330 nm excitation, the BaSrGdSbO 6 : Bi 3+ , Mn 4+ phosphors exhibited the efficient characteristic emissions of Bi 3+ and Mn 4+ ions simultaneously. The energy transfer from Bi 3+ to Mn 4+ is mainly attributed to long-range electric multipole interactions, with a possible dominant quadrupole-quadrupole contribution. Interestingly, Bi 3+ exhibits an anti-thermal quenching behavior, while Mn 4+ presents a strong thermal quenching behavior under 330 nm excitation. Based on the significantly different temperature sensitivities of Bi 3+ and Mn 4+ , a ratiometric optical thermometer with a relative sensitivity of 2.02% K −1 at 473 K was designed. The study elucidates the optical properties of Bi 3+ and Mn 4+ ions in BaSrGdSbO 6 : Bi 3+ , Mn 4+ , while underscoring the promising application of these phosphors in optical temperature sensing. Download: Download high-res image (191KB) Download: Download full-size image