Photoluminescence and scintillation properties of Si3N4-reduced Cu ions-doped gadolinium borosilicate glasses

Abstract

A series of Cu⁺ -doped 20Gd₂O₃–20B₂O₃–50SiO₂–10MgO glasses were successfully prepared using the melt-quenching method under an air atmosphere. By introducing the solid-state reducing agent Si₃N₄, the valence state of Cu ions (Cu²⁺ → Cu⁺ → Cu⁰) was effectively and controllably adjusted. Under UV or X-ray excitation, all samples exhibited broadband emission in the visible region. The sample with the most effective Si₃N₄ reduction showed the best overall performance, characterized by a photoluminescence quantum yield (PLQY) of 52.12%, a visible light transmittance of 80%, a decay time in the microsecond range, an X-ray excited luminescence (XEL) integrated intensity reaching 86.6% of Bi₄Ge₃O₁₂ (BGO), and high spatial resolution (22.0 lp/mm). These results demonstrate that using Si₃N₄ as a low-cost, safe reducing agent can effectively stabilize the Cu⁺ luminescence center, significantly enhancing the luminescence and scintillation properties of Cu⁺ -doped glasses. These results provide a new approach for developing high-performance non-rare-earth glass scintillators for X-ray imaging.