Cerium(III) bromide hybrid with near-unity photoluminescence quantum efficiency for high-resolution and fast x-ray...

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 Ce³⁺ based halide hybrids, namely [Emim]₃CeBr₆ and [Emmim]₃CeBr₆ (Emim = 1-ethyl-3-methylimidazolium; Emmim = 1-ethyl-2,3-dimethylimidazolium), both exhibiting intense broad-band violet-to-blue emission originated from Ce³⁺ 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 48,000 photons 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.