Exploring the luminescent thermometer and optical storage applications in negative thermal quenching phosphor of BaSc2Ge3O10:Pr3+

The optical contactless thermometer demonstrates remarkable advantages over traditional contact thermometers. However, maintaining a strong optical signal output across a wide temperature range poses a challenge due to the thermal quenching effect. In this study, we aimed to overcome the limitation of low signal intensity in high-temperature applications by developing a Pr3+-doped BaSc2Ge3O10 (BSGO) phosphor with anti-thermal quenching properties. This phosphor was designed to ensure a stable and sufficiently strong light signal for accurate temperature measurements. The phosphor exhibited a negative thermal quenching effect, where the integrated emission intensity spanning from 450 nm to 800 nm increased from 173 K to 253 K, and the intensity at 353 K still remained stronger than at 173 K. Multiple 4f-4f transition emissions were observed in the phosphor, and the fluorescence intensity ratio (FIR) was utilized as a standard parameter for temperature evaluation ranging from 82 K to 353 K. At 82 K, the phosphor achieved maximum relative sensitivity (Sr) of 2.3% K−1. The presence of multiple traps with depths ranging from 1.09 eV to 1.50 eV not only supported luminescence with a negative thermal quenching effect but also resulted in long persistent luminescence (LPL), which was systematically investigated in this study.