Temperature‐Inert Terbium Cluster Scintillator

ABSTRACT X‐ray scintillators play a critical role in medical diagnostics and industrial applications by converting ionizing radiation into low‐energy photons. Among various scintillators, metal clusters are promising due to advantages such as atom‐precise structures, high heavy‐atom density, strong luminescence intensity, and low usage cost. Those exhibiting temperature‐inert radioluminescence properties show broad application potential in extreme environments and have attracted considerable attention. In this work, a comprehensive strategy incorporating triplet exciton recycling and fluoride‐bridge‐induced carrier traps was introduced in the design of a temperature‐inert cluster scintillator ( Tb 16 ). The introduction of rare earth elements facilitated high‐efficiency triplet exciton recycling during the radioluminescence process, endowing Tb 16 with a high light yield of 41380 ± 950 photons MeV −1 . Meanwhile, the presence of fluoride‐bridges in Tb 16 induced abundant carrier traps, and the charge carriers captured by these traps could be thermally released back to the excited state at high temperatures, effectively compensating for emission loss. As a result, the radioluminescence intensity of Tb 16 remains nearly unchanged over a temperature range from 300 to 540 K, demonstrating its strong application potential in variable‐temperature X‐ray imaging.