High‐Density Ce ³⁺ ‐Doped Gadolinium Fluoro‐Oxide Borosilicate Scintillator Glasses for Ultra‐Thin High‐Absorption X‐Ray Imaging and Multi‐Energy γ‐Ray Detection

ABSTRACT Glass scintillators have long been considered a cost‐effective alternative to crystal scintillators, but their widespread use has been limited by low absorption, unsatisfactory light yield, and poor X‐ray imaging spatial resolution. Here, we introduce a class of Ce 3+ ‐doped gadolinium fluoro‐oxide borosilicate glasses. The synergistic incorporation of Gd 2 O 3 and GdF 3 establishes a dense matrix ( ρ ≥5.86 g/cm 3 , Z eff ≥41.6), while AlF 3 optimizes the glass network and suppresses nonradiative losses. Under X‐ray, the glass achieves a light yield of 3360 ph/MeV (42% of Bi 4 Ge 3 O 12 ), while maintaining a linear response to dose rates with a detection limit of 513 nGy/s. A 0.50 mm‐thick sample attenuates over 97% of 50.24 keV X‐rays (≥88.8% at 0.3 mm) and ≥99.9% of 22 keV X‐rays (≥99.5% at 0.3 mm). These properties, coupled with outstanding processability, enable the fabrication of scintillators as thin as 300 µm, facilitating ultrathin, high‐absorption X‐ray imaging with spatial resolution reaching ∼23 lp/mm. Owing to high‐density, the glasses also exhibit strong γ‐ray responsiveness across multiple isotopes, including 137 Cs, 22 Na, 133 Ba, 177 Lu, and 228 Th, with a light yield of 1620 ph/MeV at 662 keV. The linear correlation between the ADC channels of full‐energy peaks and photon energy highlights the potential for γ‐ray screening of radioactive elements.