Data-Driven Exploration of the Ionization-Phonon Partitioning in Scintillating Radiation Detector Materials

An information-based approach to scintillating materials development has been applied to ranking the alkali halide and alkaline earth halide series in terms of their energy conversion efficiency. The efficiency of scintillating radiation detection materials can be viewed as the product of a consecutive series of electronic processes (energy conversion, transfer, and luminescence) as outlined by Lempicki and others. Relevant data are relatively sparse, but sufficient for the development of forward mapping of materials properties through materials signatures. These mappings have been used to explore the limits of the branching ratio between the ionization and phonons (K) in the Lempicki model with chemical composition, and examine its relationship with another common design objective, density. The alkali halides and alkaline earth halide compounds separate themselves into distinct behavior classes favoring heavier cations and anions for improved values of the K ratio. While the coupling of ionization is strongly related to the optical phonon modes, both dielectric and band gap contributions cannot be ignored. When applied as a candidate screen, the resulting model for K suggests design rules—simple structural restrictions—on scintillating radiation detector materials.