Tunable valence state and scintillation performance of dense Ce3+-doped borosilicate glasses prepared in ambient atmosphere

Abstract

A series of Ce³⁺-doped borosilicate glass scintillators (GABS_x) was successfully synthesized in ambient atmosphere. The cut-off wavelength was observed to change slightly in the range of 335–345 nm, which was related to the concentration ratios of Ce³⁺ to Ce⁴⁺ in the GABS_x glasses. X-ray absorption near edge structure (XANES) spectra indicate that the valence state of cerium was effectively adjusted using various contents of Si₃N₄ powder as a reducing agent in the air atmosphere. Under ultraviolet excitation, the glasses show a broadband emission in the 320–600 nm wavelength regions. The PL decay time of the GABS_x glasses is around 23 ns, and the maximum PL QY reaches 72.51%. The integral X-ray excited luminescence (XEL) intensity of the GABS_1.0 glass is 11.8% of Bi₄Ge₃O₁₂ (BGO) crystal. Under γ-ray irradiation, the light yield of all glasses exceeds 1000 ph MeV⁻¹ as the Si₃N₄ concentration increases. The highest light yield of GABS_1.0 glass reaches 1279 ph MeV⁻¹ with an energy resolution of 27.1% at 662 keV. All the glasses exhibited a scintillation decay time of approximately 820–873 ns, which is much slower than those of photoluminescence (PL) decay time of about 26 ns by a factor of over 30. Thermally stimulated luminescence (TSL) curves were recorded to explore the nature of the defects in the glasses. Therefore, the potential application of the investigated GABS_x glasses is promising, but performance optimization for practical high-energy physics engineering is needed.