Solvent‐Mediated Structural and Luminescence Diversification of Organic Copper(I) Halides

Low‐dimensional organic‐inorganic hybrid halides have emerged as a new kind of promising scintillators owing to their high light output and tunable emission across the full visible spectrum. Exploration of new Cu‐based halides for x‐ray applications has become a current research hotspot. Herein, we performed a solvent‐mediated structural design strategy and prepared two new Cu(I)‐based halides of (AEMP) 4 [Cu 2 Br 6 ] 3 and (AEMP)[Cu 3 Br 6 ]·H 2 O (AEMP = 1‐(2‐Aminoethyl)‐4‐Methyl‐Piperazine), in a system. Interestingly, (AEMP) 4 [Cu 2 Br 6 ] 3 contains 0D [Cu 2 Br 6 ] 4− dimer, while (AEMP)[Cu 3 Br 6 ]·H 2 O is composed of 1D [Cu 3 Br 6 ] 3− chain building from corner‐shared [Cu 3 Br 6 ] trimers. In contrast to unstable (AEMP) 4 [Cu 2 Br 6 ] 3 , (AEMP)[Cu 3 Br 6 ]·H 2 O exhibits stable and highly efficient photoluminescence and radioluminescence emission with a near‐unity photoluminescence quantum yield of 99.45% and a promising radioluminescence light yield of 27,185 photons MeV −1 , respectively. Meanwhile, the detection limit of 66.31 n Gy air s −1 is much lower than the x‐ray dose required for diagnosis (5.5 µ Gy air s −1 ). A flexible film with excellent foldability and crack resistance was fabricated for x‐ray imaging, which achieves a high spatial resolution of 10 lp mm −1 . Combining multiple advantages, including low cost, high luminescence efficiency, and excellent scintillation performance, enable this cuprous halide to stand out as a promising x‐ray scintillator.