White Light Emission of Gadolinium Calcium Phosphate Oxide and Oxyfluoride Glasses Doped with Dy3+

The oxide (20Gd(2)O(3)-10CaO-69P(2)O(5)) and oxyfluoride glasses (20Gd(2)O(3)-10CaF(2)-69P(2)O(5), 20GdF(3)-10CaO-69P(2)O(5) and 20GdF(3)-10CaF(2)-69P(2)O(5)) doped with dysprosium oxide (Dy2O3) were prepared by melt quenching technique. They were characterized through absorption and luminescence properties. The oxide and oxyfluoride glasses are compared for studying fluoride ions results. For the absorption results, the glass absorbed light in visible and near-infrared region by start from H-6(15/2) ground state to higher state. The oxyfluoride glasses can absorb light greater than oxide glass, notwithstanding that the fluoride ions are not affect to absorption intensity, normally. The Judd-Ofelt (JO) parameters (Omega(lambda), lambda = 2, 4 and 6) are analyzed from absorption results. All glasses show a similar trend of JO parameter is Omega(2) > Omega(6) > Omega(4). The radiative transition probabilities (A(R)), stimulated emission cross-sections (sigma(lambda(p))) and branching ratios (beta) obtained from using JO parameter. The emission spectra of all glasses present more intense at 483 nm (blue light) and 573 nm (yellow light) which are essential for white light emitting materials. However, the emission spectra of oxyfluoride glasses are higher than oxide glass due to the reduction of phonon energy. The integral scintillation efficiency of 20GdF(3)-10CaF(2)-69P(2)O(5) doped Dy2O3 glass is compared with commercial Bi4Ge3O12 (BGO) crystal by radioluminescence spectra. It is determined at 35% of BGO crystal. (C) 2018 Elsevier Ltd. All rights reserved.