Pixelated Scintillator Arrays with Si-SiO₂ Waveguiding Architecture for High-Resolution x-ray Imaging

High spatial resolution and sensitivity are critical performance metrics for x-ray imaging systems. Traditional thick polycrystalline scintillators suffer from severe internal light scattering, which limits imaging resolution and low-dose detection capability. Here, we present a pixelated scintillation screen with a waveguide architecture based on a Si-SiO₂ array (SOA) template, in which crystalline Cs₅Cu₃Cl₆I₂, a low-dimensional perovskite-like halide, is used as the scintillation medium. The low-refractive-index SiO₂ layer enables total internal reflection (TIR) for vertical photon guidance, while the Si substrate provides both high x-ray transmittance and visible light absorption, effectively reducing optical crosstalk. Using a vacuum-assisted infiltration process, Cs₅Cu₃Cl₆I₂ is infiltrated and recrystallized within the SOA channels, yielding a well-confined scintillator structure that suppresses lateral scattering and enhances vertical photon transport. Compared to conventional film-based scintillators, the SOA-based design exhibits markedly improved imaging performance, achieving a spatial resolution of 20.10 lp·mm^-1 and a minimum detectable dose of 35 nGy·s^-1. In addition, the fabrication process is highly scalable, allowing flexible construction of scintillator arrays with tailored pixel sizes and layouts. This approach provides a promising strategy for next-generation x-ray imaging with simultaneously high resolution and low-dose sensitivity.