Tunable Luminescence and Efficient Energy Transfer Investigation of a Novel Borosilicate Phosphor Kbsi2o6: Bi3+, Eu3+ with Hypersensitive Thermal Quenching

Abstract

Energy transfer between Bi3+ and Eu3+ has undergone substantial research but Bi3+/Eu3+ co-doping luminescent materials for temperature sensing are rarely mentioned until now. Herein, Eu3+/Bi3+ co-activated KBSi2O6 phosphors were synthesized at 1000°C and the process of energy transfer has been studied as well as the potential application in the temperature sensing field. By directly witnessing a sizable overlap between the spectrum of Bi3+ and Eu3+, the energy transfer from Bi3+ to Eu3+ can be inferred. The consistent lifetime decline and rising intensity of the Eu3+ emission peak provide additional evidence of the effective energy transfer from Bi3+ to Eu3+. By increasing the Eu3+ concentration in KBSi2O6: Bi3+, Eu3+ samples, the color-tunable emission from blue to red can be observed. The fluorescence intensity ratio (FIR) exhibits exceptional temperature sensing abilities by using the emission spectra of KBSi2O6: Bi3+, Eu3+. The maximum absolute and relative sensitivities are, respectively, 1.87%K-1 and 2.895%K-1. All of the aforementioned findings imply that KBSi2O6: Bi3+, Eu3+ phosphor might be a viable substitute phosphor for optical thermometers.

Keywords: Luminescence property, Energy transfers, Optical thermometer