Physical and photoluminescence investigations of Eu3+ doped gadolinium borate scintillating glass

The bright reddish-orange emitting Eu3+-doped gadolinium borate glasses of 25Gd2O3-(75-x) B2O3-xEu2O3 (GdBEu) (x = 0.1, 0.3, 0.5, 1.0, 3.0, 5.0, 7.0, and 9.0 mol%) were fabricated by melt-quenching technique at 1400 °C for 3 h. All GdBEu glasses were investigated the photoluminescence, scintillation, and lasing potential properties. The energy transfer processes from Gd3+→Eu3+ in these glasses were discovered. Photons in the ultraviolet, visible, and near-infrared region wavelengths were absorbed by glasses. The photoluminescence excitations were performed at 275 nm and 394 nm, respectively. When the energy transferred from Gd3+ to Eu3+, luminescence features revealed an intense red emission with a wavelength of 614 nm (5D0 → 7F2). The glass's optimum Eu3+ ion concentration was 7.0 mol%, corresponding to the maximum emission intensity. Judd-Ofelt parameters were calculated from the emission spectra and the radiative properties of several excited states were examined, including the transition probability (AR), branching ratio (βR), stimulated emission cross-section (σe), and decay time (τR). Once the Eu3+ concentration increased from 0.1 to 9.0 mol%, the decay time of the 5D0 level dropped from 1.824 ms to 1.585 ms. The colors of glasses were confirmed by the Commission internationale de l'éclairage (CIE) chromaticity diagram. The glass samples had a peak area of radioluminescence (RL) spectrum 18% of BGO scintilltation crystal.