Large-area flexible scintillator screen based on copper-based halides for sensitive and stable X-ray imaging

X-ray scintillators, which convert high-energy radiation into visible light signals, have been rapidly developed for their widespread use in medical, security, and commercial diagnostic technologies. However, the development of large-area flexible scintillator screens with excellent stability and scintillation performance for non-planar objects is relatively lagging behind. Here, we fabricated large-area flexible scintillator screens with excellent stability and scintillation properties by loading nanoscale Cs3Cu2I5 particles into an elastic polydimethylsiloxane (PDMS) matrix. Copper halide Cs3Cu2I5, with self-trapped exciton emission, exhibits intense blue emission with a large Stokes shift, which can effectively reduce the light self-absorption effect. The experimental results reveal that the PDMS matrix can effectively passivate the surface defects of Cs3Cu2I5 particles, improve the exciton binding energy and ensure effective exciton recombination, thereby achieving more efficient optical coupling efficiency. In addition, the Cs3Cu2I5@PDMS flexible film exhibits excellent thermal stability, photostability, and water stability, and the radiative luminescence intensity does not decay after a continuous irradiation for 100 min under high-dose X-rays. Large-area flexible scintillator screen with uniform luminescence achieves a high spatial resolution of 8.6 lp/mm and a high light yield of 46000 photons/MeV, and exhibits excellent linear response to X-ray dose rate and low detection limit of 96.54 nGyair/s. Moreover, the large-area flexible scintillator screen exhibits high-quality X-ray imaging for both planar and non-planar objects. Our results demonstrate that the stable and sensitive Cs3Cu2I5@PDMS scintillator screen may have promising application prospects in flexible X-ray imaging fields.