Bright Cu-Doped Silver-Based Perovskite Scintillators for X-Ray and Neutron Detection and Their Unique Excitonic Behaviors

Ag-based perovskite scintillators have recently attracted significant interest for X-ray imaging due to their high light yield and ultra-fast 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 perovskite scintillators for 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% and the scintillation screen achieved a high resolution of 12 lp/mm. 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 13,000 photons/thermal neutron, which is 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. Moreover, we propose two types of self-trapped exciton behaviors which has been proved by low temperature spectra and femtosecond UV-Vis transient spectra, which has not been reported in previous research. Our work provides a new strategy for large-scale, perovskite-based X-ray imaging and thermal neutron detection screens.