Insight into temperature-dependent photoluminescence of LaOBr: Ce3+, Tb3+ phosphor as a ratiometric and colorimetric luminescent thermometer

Abstract A dual-emitting phosphor LaOBr: Ce 3+ , Tb 3+ was synthesized, and the corresponding temperature-dependent luminescent properties were systematically investigated. The dual-emitting phosphor exhibits an exactly contrary thermal dependence with respect to the blue emission of the Ce 3+ sensitizer and the green emission of the Tb 3+ activator. The unique energy transfer between Ce 3+ and Tb 3+ enables this luminescent thermometer to be highly temperature-sensitive over a wide temperature range. The fluorescence intensity ratio (FIR) of the blue and green emission bands peaked at 430 and 543 nm is found to have a well-fitted linear relationship with respect to temperature, and the emitting color shifts from blue to green when temperature rises from 273 K to 493 K. The results indicate that Ce 3+ , Tb 3+ co-doped LaOBr phosphor is a potential candidate for a ratiometric and colorimetric luminescent thermometer.