Recently, the ‘Tongji Crystal’ team from the School of Physical Science and Engineering at Tongji University has achieved a significant breakthrough in the research of high-entropy fluoride inorganic scintillator materials. Their groundbreaking findings have been published in Science China Materials under the title “Ultrafast Scintillation Enabled by Exciton Localization in High-Entropy Fluoride Crystals.”

This study introduces an innovative design strategy for ultrafast scintillators based on the regulation of exciton dynamics through high-entropy lattice distortion. By incorporating the principles of high-entropy material design, the team successfully cultivated large-sized Ce-ion-doped LaGdCaSrBaF₁₂ (Ce:LGCSB) high-entropy fluoride single crystals. This novel material leverages substantial local lattice distortion and electric field perturbations caused by multiple cations co-occupying lattice sites. These perturbations facilitate exciton localization and suppress their long-range diffusion, resulting in an ultrafast scintillation decay of approximately 1 nanosecond. This achievement places it among the fastest Ce-activated bulk scintillation crystals currently available.

Experimental results demonstrate that samples with varying Ce concentrations achieved scintillation decay times of 1.23 nanoseconds, 1.97 nanoseconds, and 2.56 nanoseconds, respectively, with no significant long-lived slow components detected. This breakthrough offers fresh perspectives for the development of advanced ultrafast scintillation materials, with potential applications in high-frame-rate X-ray imaging, time-of-flight positron emission tomography (TOF-PET), and high-energy physics detection.

The research received support from key projects such as the National Key Research and Development Program and the National Natural Science Foundation of China.