Highly efficient luminescence in bulk transparent Sr2GdF7:Tb3+ glass ceramic for potential X-ray detection

Near UV–blue emission from Ce doped Y2SiO5 phosphor

Extensive researches on scintillators have been executed to satisfy the excellent radiation detection materials in broad applications. However, practical application of conventional scintillators is limited due to the limitations of high cost, time-consuming fabrication process and insufficient radioluminescence. Herein, high density precursor glass doped with Tb3+ was designed to absorb X-ray efficiently and produce green emission. Molecular dynamics simulation was used to simulate the phase separation process in melting process. Then, Tb3+-doped Ba0.84Gd0.16F2.16 glass ceramics (GCs) with excellent structural and optical properties were elaborated by melt quenching technic and further heat treating. Their structural properties, photoluminescence (PL) and X-ray excited luminescence (XEL) were explored detailedly. The internal quantum efficiency of PL is 64 % in GCs. The XEL intensity is 192 % of that of Bi4Ge3O12 (BGO) commercial scintillator. Our results suggest that Ba0.84Gd0.16F2.16:Tb3+ GCs might have potential application in X-ray detection.

Design, simulation, elaboration and luminescence of Tb3+-doped Ba0.84Gd0.16F2.16 fluoroaluminosilicate scintillating glass ceramics

Absorption, electron spin resonance, and photo- and thermally stimulated luminescence characteristics are studied for single crystalline films (SCFs) of Y2SiO5?:?Ce and Lu2SiO5?:?Ce prepared by the liquid phase epitaxy method with the use of a PbO-containing flux. They are also compared with the characteristics of the corresponding single crystals (SCs) as well as of the undoped Y2SiO5 and Lu2SiO5 SCFs and SCs. The concentration of stable trivalent Ce3+ ions in various SCFs with different lead and cerium contents is found to be negligible. It is suggested that stable tetravalent Ce4+ ions mainly exist in the SCF due to a large concentration of Pb2+ ions whose excess volume and negative charge can be effectively compensated by relatively small tetravalent Ce4+ ions. Nevertheless, the characteristic Ce3+ emission in the SCFs of Y2SiO5?:?Ce and Lu2SiO5?:?Ce does appear under photoexcitation in the charge-transfer absorption region (Eexc?>?4.2?eV), most probably as a result of the two-photon excitation process. Ce3+ emission is observed under excitation by the ionizing radiation as well and is explained by the recombination of free electrons from the conduction band with Ce4+ ions.

V.V. Gorbenko

Papers

Scintillation and luminescent properties of undoped and Ce3+ doped Y2SiO5 and Lu2SiO5 single crystalline films grown by LPE method