Luminescent Organic\nSingle Crystals for Flexible Optical\nFiber Scintillators and X‑ray Imaging

Optical fiber-based glass scintillators are high-efficiency\nscintillators\nwith excellent light collection and transmission properties. However,\nthe performance of optical fiber scintillators is constrained by structural\ndefects in silicate glass and reduced transparency due to doping.\nTo overcome this limitation, we report a high-quality elastic crystal\nof a Schiff base, (<i>E</i>)-1-(((4-bromophenyl)imino)methyl)naphtha-len-2-ol\n(BPIN). The one-dimensional crystal exhibits exceptional elasticity\nand high fracture strength. The dominant π···π\ninteractions and C–H···Br interactions in the\ncrystal contribute significantly to the bending behavior. Moreover,\nowing to the heavy atom effect that enhances X-ray absorption capability,\nBPIN demonstrates outstanding scintillation performance with a fast\nradiative lifetime of 2.90 ns and low detection of 0.11 μGy<sub>air</sub> s<sup>–1</sup>. Based on the waveguiding and scintillation\nproperties of BPIN, we propose a flexible crystal optical fiber scintillator.\nFurthermore, by expanding the crystal morphology to two dimensions,\na high-resolution X-ray imaging screen is realized. Our study introduces\nan innovative approach for utilizing organic crystals in high-performance\nflexible X-ray detectors and imaging.