Blue‐Cyan Emitting Eu ²⁺ ‐Doped Oxyfluoride Glass for X‐ray Scintillator and White LED

ABSTRACT Eu 2+ ‐doped glass has received widespread attention for its potential in multifunctional applications of X‐ray imaging and white light‐emitting diode (LED). However, the disorder of glass structure poses a great challenge for improving the luminescent efficiency of Eu 2+ in glass. Herein, the strategies of phase separation in oxyfluoride glass, reduction by C powders, and energy transfer from Gd 3+ to Eu 2+ are proposed for constructing blue‐cyan emitting Eu 2+ ‐doped glass with excellent X‐ray excited luminescent (XEL) and photoluminescent (PL) performance. For scintillating performance, the XEL intensity of optimal sample reaches 205% of that of commercial Bi 4 Ge 3 O 12 , setting a record‐breaking value among Eu 2+ ‐doped glass. Combining with high transmittance (>80% at 470 nm), perfect linear response to X‐ray, and low limit of detection (6.6 µGy air /s), the optimal sample shows a remarkable imaging resolution of 20 lp/mm. For PL, the optimal sample emits intense blue‐cyan light with high external quantum efficiency of 50.4% and excellent thermal stability (PL intensity at 423 K remains 57.9% of that at room temperature). It complements the cyan gap of commercial full‐spectra white LED and improves the color rendering index to 92.5. This work provides important references and insights for enhancing the XEL and PL performance of Eu 2+ ‐doped glass.