Cuprous-based layered single-crystalline scintillators for X-ray detection and imaging†

High light yield, low detection limit, large X-ray attenuation efficiency and nontoxic composition are critical features of scintillators for ionizing radiation detection. We herein demonstrated a new layered organic–inorganic hybrid cuprous iodide single crystal (C₆H₁₀N₂)₂Cu₂I₃(PO₂)₃ (C₆H₁₀N₂²⁺ = 1,4-phenylenediaminium) for X-ray detection and imaging. Upon UV light excitation, (C₆H₁₀N₂)₂Cu₂I₃(PO₂)₃ displays highly efficient yellow light emission with one dominant peak located at 578 nm, a large Stokes shift of 160 nm, and a high photoluminescence quantum yield (PLQY) of 96.4%. This crystal could also exhibit radioluminescence with a high scintillation light yield of 32 000 photons MeV⁻¹. A detection limit of ∼39 nGy_air s⁻¹ is determined, which is far lower than the required value of 5.5 μGy_air s⁻¹ for regular medical diagnostics. Moreover, the (C₆H₁₀N₂)₂Cu₂I₃(PO₂)₃-based scintillation screen exhibits high-performance for X-ray imaging with a spatial resolution of 11.14 lp mm⁻¹, indicating the great potential in X-ray radiography. In brief, combined merits of low toxicity and cost, negligible self-absorption, a low detection limit, a high light yield and a spatial resolution make (C₆H₁₀N₂)₂Cu₂I₃(PO₂)₃ an excellent candidate for X-ray scintillation.