Zero-Dimensional Copper(I) Halide Microcrystals as Highly Efficient Scintillators for Flexible X‑ray Imaging

Commercially available rare-earth-doped inorganic oxide
materials
have been widely applied as X-ray scintillators, but the fragile characteristics,
high detection limit, and harsh preparation condition seriously restrict
their wide applications. Furthermore, it remains a huge challenge
to realize X-ray flexible imaging technology for real-time monitoring
of the curving interface of complex devices. To address these issues,
we herein report two isostructural cuprous halides of zero-dimensional
(0D) [AEPipz]CuX3·X·H2O (AEPipz = N-aminoethylpiperazine, X = Br and I) with controllable
size to nanosize crystal as highly efficient scintillators toward
flexible X-ray imaging. These cuprous halides exhibit highly efficient
cyan photoluminescence and radioluminescence emissions with the highest
quantum yield of 92.1% and light yield of 62,400 photons MeV–1, respectively, surpassing most of the commercially available inorganic
scintillators. Meanwhile, the ultralow detection limit of 95.7 nGyair s–1 was far below the
X-ray dose required for diagnosis (5.5 μGyair s–1). More significantly, the flexible
film is facilely assembled with excellent foldability and high crack
resistance, which further acts as a scintillation screen achieving
a high spatial resolution of 17.4 lp mm–1 in X-ray
imaging, demonstrating the potential application in wearable radiation
radiography. The combined advantages of high light yield, low detection
limit, and excellent flexibility promote these 0D cuprous halides
as the most promising X-ray scintillators.