Cu-Doped Cs₂AgI₃ Composite-Loaded Plastic Scintillators for X-Ray and Thermal Neutron Detection

Abstract

Ag-based metal halide scintillators have recently attracted significant interest for X-ray imaging due to their high light yield and ultrafast decay lifetime. These properties are advantageous for thermal neutron detection, yet their application in this area has not been thoroughly explored. In this article, we investigate the properties of Cu-doped Cs2AgI3 metal halide scintillators for X-ray imaging and thermal neutron detection. A simple synthesis process was employed to produce Cu-doped Cs2AgI3 scintillators. The as-prepared Cu-doped Cs2AgI3 exhibited intense green emission with a photoluminescence quantum yield (PLQY) of 55% $\pm ~2.7$ %. The Cu-doped Cs2AgI3/poly(vinylidene fluoride) (PVDF) plastic scintillation screen has been prepared and achieved a resolution of 5 lp/mm under X-ray radiation. A composite consisting of 6LiF, Cu-doped Cs2AgI3, and poly(methyl methacrylate) (PMMA) was utilized for thermal neutron detection, achieving a light yield of about 12 $526~\pm ~9$ photons/thermal neutron, which is almost twice that of a commercial 6Li-glass (GS20) scintillator (7000 photons/thermal neutron). Effective neutron-gamma pulse discrimination was achieved using a network dynamics digital filter, effectively separating thermal neutron events from gamma events.