Tunable luminescence and energy transfer from Gd3+ to Tb3+ ions in silicate oxyfluoride scintillating glasses via varying Tb3+ concentration

Abstract Silicate oxyfluoride scintillating glasses doped Tb 3 + with different concentrations were prepared by a melt-quenching method. The detailed analyses of photoluminescence spectra and luminescence decay curve testified that the Gd 3 + indeed transfers their energy to Tb 3 + via phonon assistant electric dipole–dipole interaction. The evaluated energy transfer efficiency from Gd 3 + to Tb 3 + increases gradually with increasing the Tb 2 O 3 content and reaches 99% when the content of Tb 2 O 3 exceeds 5 mol%. Due to the more efficient energy transfer from Gd 3 + to Tb 3 + and higher doping concentration of Tb 3 + , the intensity of green emission originated from 5 D 4 → 7 F J reaching the maximum when the content of Tb 2 O 3 is 6 mol%. Meanwhile, a strong 5 D 3 luminescence quenching happens due to the cross-relaxation process. Under X-ray excitation, the intensity of 542 nm emission in our glass doped with 6 mol% of Tb 2 O 3 shows 5.2 times stronger than that of 500 nm emission in the commercial Bi 4 Ge 3 O 12 (BGO) crystal, the integral scintillation efficiency is about 68% of the BGO crystal, which is much useful for reducing radiative dose to obtain high-resolution X-ray imaging.