Ceramic Wafer Scintillation Screen by Utilizing Near-Unity Blue-Emitting Lead-Free Metal Halide (C8H20N)2Cu2Br4

Scintillators with high light yield, low detection limit, large X-ray attenuation efficiency as well as stable and nontoxic compositions are of great importance for radiation detection applications. Here, 0D (C 8 H 20 N) 2 Cu 2 Br 4 single crystals are obtained and show blue emission peaking at 468 nm with a near-unity photoluminescence quantum yield of 99.7%, a large Stokes shift of 148 nm (i.e., negligible self-absorption), and a good environmental stability along with strong X-ray absorption capability. Moreover, a high light yield of up to ≈ 91 300 photons/MeV and a low detection limit of 52.1 nGy air s −1 are realized, which is more than one hundred times lower than the dose rate of 5.5 µGy air s −1 required for X-ray medical diagnostics. (C 8 H 20 N) 2 Cu 2 Br 4 ceramic wafer scintillation screen is fabricated by a cold pressing sintering process, and the clear contrast images of opaque metal box and electronic component with a spatial resolution of 9.54 lp mm −1 are realized. This study not only designs a new lead-free metal halide scintillator, but also develops a universal strategy for the preparation of large-sized scintillator screen in nondestructive X-ray imaging.