Solvent Engineering for Transparent Dispersion of Large Fluoride Scintillating Particles

The resolution ability of X‐ray imaging screen relies heavily on both the composite transparency and the loading content of scintillating particles, where the tradeoff in between remains elusive. Herein, we report a transparent scintillator of liquid composite involving a high‐loading content of fluoride microparticles in a compatible solvent. Theoretical simulations based on Mie scattering theory are used to demonstrate that even for large microparticles, light scattering can be largely suppressed by minimizing the refractive index (RI) contrast ( Δn = |n solvent —n MP | ) between the particles and the dispersion medium. Experimentally, it is found that a slight RI difference from 0.0325 to 0.0030 leads to a remarkable increase in the transmittance of the dispersion system from 4.1% to 85.5%, allowing the formation of a transparent liquid scintillator of high‐loading fillers up to 65 wt.%. As a proof‐of‐concept, the scintillator was used in X‐ray imaging and fiber‐optic devices. This work not only overcomes the limitations of composite screen associated with particle scattering of output light, but also opens many avenues to those transparent display techniques.