0D Hybrid Cuprous Halide as an Efficient Light Emitter and X-Ray Scintillator

Despite the extraordinary X-ray scintillation performance of three-dimensional (3D) lead perovskite nanocrystals (PNCs), the serious biotoxicity of Pb 2+ and luminescent instability in water remain insurmountable obstacles for their applications in medical imaging. To address these drawbacks, herein, the study demonstrates one new lead-free zero-dimensional (0D) hybrid cuprous halide of single-crystalline [BzTPP] 2 Cu 2 I 4 (BzTPP = Benzyltriphenylphosphonium) as a satisfactory X-ray scintillator. [BzTPP] 2 Cu 2 I 4 displays broadband yellowish-green light emission with a high photoluminescent quantum yield (PLQY) of 44.2% and large Stokes shift of 167 nm upon UV light excitation. High PLQY and negligible self-absorption enable [BzTPP] 2 Cu 2 I 4 to display impressive scintillation performance excited by X-ray with a light yield of 27 706 photons MeV -1 and low detection limit of 0.352 µ Gy s −1 , surpassing typical 3D PNCs. More importantly, [BzTPP] 2 Cu 2 I 4 represents extraordinary structural and luminescent stability in water for at least one month. The excellent and stable radioluminescence performance as well as solution growth method ensure a [BzTPP] 2 Cu 2 I 4 -based screen for fine-resolution X-ray imaging with potential in radiography and inspection. This work highlights the multiple merits of low-toxicity and cost, high light yield, and long-term water-stability of 0D hybrid cuprous halides as highly desirable X-ray scintillators.