Ce 3+ ‐Activated Lithium‐Rich Borosilicate Glass Scintillator for γ‐Ray Detection

High‐density Ce 3+ ‐doped lithium‐rich gadolinium borosilicate oxyfluoride glasses (Gd 2 O 3 –GdF 3 –Al 2 O 3 –B 2 O 3 –SiO 2 –LiF– x CeF 3 , x = 0–5 mol%, abbreviation GBSFAL x ) were prepared by melt quenching in a reducing atmosphere for γ‐ray detection. All samples show greater than 80% transmittance in the visible range (400–700 nm). With increasing CeF 3 content, the absorption edge red‐shifts (328→341 nm) and the Ce 3+ emission peak shifts to longer wavelengths. The maximum photoluminescence quantum yield (PLQY) of these glasses is 71.95%, and the photoluminescence (PL) decay time is in the range of 40–43 ns. For scintillation, the integral X‐ray‐excited luminescence (XEL) intensity of GBSFAL 3 glass is 62.85% of that of the Bi 4 Ge 3 O 12 (BGO) crystal. Under irradiation from a 137 Cs γ‐ray source, the light yield (LY) reached up to 1491 ph/MeV with an energy resolution of 26.9%. All glasses exhibit a double exponential scintillation decay time, which consists of fast (69.5–114.3 ns) and slow (311.6–1018.2 ns) components, respectively. The glasses with various concentrations of Ce 3+ were investigated through thermally stimulated luminescence (TSL). The concentration of CeF 3 modifies the trap state distribution, with shallow and intermediate traps becoming more abundant relative to deep traps as Ce 3+ concentration increases, thereby improving the light yield. Therefore, GBSFAL x glass scintillators represent a potential solution for a future alternative to conventional low‐density glass scintillators for γ‐ray detection applications.