Sn²⁺‐Doped High‐Density Gadolinium Borosilicate Glass Scintillator for X‐Ray Imaging

Abstract

High‐density scintillator glasses offer significant promise for advanced X‐ray imaging, particularly in X‐CT and compact X‐ray detection systems. In this study, a series of Sn²⁺‐doped gadolinium‐based scintillator glasses (SBGA:xSn²⁺) is synthesized, which exhibit densities of ≈6 g cm⁻³. These glasses demonstrate broad emission bands ranging from 330 to 670 nm, with a maximum photoluminescence quantum yield of 75.1% and a shortest photoluminescence decay time of 11 µs. Owing to the high density and substantial Gd³⁺ content, the X‐ray absorption coefficient of SBGA:1.0Sn²⁺ glass rivals that of established scintillators, such as Bi₄Ge₃O₁₂(BGO) and CsI:Tl crystals. A 600 µm‐thick SBGA:1.0Sn²⁺ glass effectively attenuates over 99% of incident X‐ray photons of 50 keV, highlighting shielding capability. Furthermore, the SBGA:xSn²⁺ glass demonstrates optical transparency of 85% in the visible range and X‐ray excitation luminescence intensity at 40.5% of that of BGO. Importantly, the SBGA:1.0Sn²⁺ glass possesses X‐ray imaging capabilities, achieving a spatial resolution of 14 lp mm⁻¹. These results represent the highest spatial resolution achieved in X‐ray imaging using high‐density glasses (≥6.0 g cm⁻³), specifically a scintillating glass in which tin (Sn) acts as the luminescent center, offering a cost‐effective alternative to traditional scintillators.