Scintillation performance of 1-inch-diameter Cs2ZnCl4 crystals

Abstract

Since the 20th century, only a few scintillators have been able to meet the demands for ultra-fast decay time ranging from several nanosecond or sub-nanosecond. Cs₂ZnCl₄ has attracted significant attention due to its excellent timing performance. However, current research on Cs₂ZnCl₄ has only focused on small-size doping, with few studies investigating pure Cs₂ZnCl₄ single crystals. In this study, we report the successful growth of 1-inch-diameter pure Cs₂ZnCl₄ crystals using the Bridgman method, resulting in a significantly larger crystal size than most previously reported pure Cs₂ZnCl₄ crystals. Notably, the peaks of the crystal's radiant luminescence were observed at 272 and 384 nm, which were attributed to core-valence luminescence. Furthermore, the theoretical band gap and state density distribution of Cs₂ZnCl₄ were determined through Vienna Ab initio Simulation Package calculations based on the structural data, and the luminescence mechanism of Cs₂ZnCl₄ was elucidated. The light output of Cs₂ZnCl₄ crystal reached 1158 ± 0.69 ph MeV⁻¹ at 662 keV, and the scintillation decay time was 1.71 ns. The centimeter-sized pure Cs₂ZnCl₄ crystal exhibited excellent optical and scintillation properties, demonstrating its significant potential for future applications in radiation detection.