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 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. Two cerium bromide hybrids [Emim] 3 CeBr 6 and [Emmim] 3 CeBr 6 (Emim = 1-ethyl-3-methylimidazolium; Emmim = 1-ethyl-2,3-dimethylimidazolium) exhibit intense 4f – 5d violet-to-blue emission from Ce 3+ with photoluminescence quantum yield of 100%. The short nanosecond decay time and the heavy atom endows two compounds with high-resolution and fast X-ray imaging property with light yield up to 48,000 pH MeV -1 and low detection limit of 626 nGy s -1 .