Dual-sensitized Gd-based oxyfluoride glass with enhanced scintillation for superior X-ray imaging

Rare-earth-doped glasses have been demonstrated as highly promising scintillator materials, particularly for X-ray imaging applications. However, challenges such as high defect density, low luminescence efficiency, poor spatial resolution remain, primarily attributed to high phonon energy, inefficient energy transfer, and light scattering in glass materials. Herein, we report a successfully designed dual-sensitized co-doped Gd-based oxyfluoride glass scintillator that can achieve high internal quantum efficiency (97.5 %), excellent X-ray luminescence (XEL) intensity (216 % Bi₄Ge₃O₁₂), high optical transparency (approximately 90 % at 550 nm), and good radiation stability by using Tb³⁺ as the luminescent center synergistically incorporating Gd³⁺ and Ce³⁺. Specifically, the optimized glass scintillator can achieve a spatial resolution of up to 32.6 lp∙mm^-1 for X-ray imaging, coupled with an exceptionally low detection limit of 1.05 μ∙Gy^-1. Additionally, the developed glass scintillator enables irregular-shaped and large-scale fabrication (diameter: 5 cm) that is difficult to accomplish with conventional scintillator materials. The developed material offers a new option for developing low-cost, high-performance glass scintillators for high-resolution X-ray imaging.