Cerium(III) Bromide Hybrid with Near-Unity Photoluminescence Quantum Efficiency for High-Resolution and Fast X-ray Imaging

Trivalent lanthanide Ce(III) with a typical allowed 4f – 5d transition generally exhibits short decay time in a nanosecond level, beneficial to fast X-ray imaging applications. Herein, we rationally design and synthesize two zero-dimensional Ce 3+ based halide hybrids, namely [Emim] 3 CeBr 6 and [Emmim] 3 CeBr 6 (Emim = 1-ethyl-3-methylimidazolium; Emmim = 1-ethyl-2,3-dimethylimidazolium), both exhibiting intense broad-band violet-to-blue emission originated from Ce 3+ with near-unity photoluminescence quantum yield. The short nanosecond decay time and the heavy atom effect further inspire us to explore their X-ray scintillation performance. Up to 48000 ph MeV -1 light yield is derived together with the low detection limit (around 626 nGy s -1 ), and thus a composite film is fabricated to achieve dynamic fast X-ray imaging. This study enlarges the family of scintillators in Ce(III)-based halide hybrid with short decay time.