LAUSR

Abstract The glass samples with the composition (50Bi2O3 + 5TeO2 + 1Dy2O3 + xSiO2+ (45-x) B2O3) where x=10, 15, 20, 25, 30 and 35 mol % prepared. Density increased and the molar volume decreased with increasing the silicon content, which reveals that the glass samples became more compact as the SiO2 increased. XRD showed that all glass samples were amorphous, The FTIR data indicated the existence of TeO3, BiO6, BO4, BO3, and SiO4 (with one non-bridging oxygen (Q3)) structural groups. UV–VIS–IR spectra revealed the presence of five bands from 6H15/2 to the 6F5/2, 6H5/2, 6F9/2, 6H9/2 and 6H11/2 according to the energy levels 12500, 11210, 9225, 7911, and 5952 cm-1 respectively. The emission spectra showed two emission bands at around 480 nm and 575 nm corresponding to the 4F9/2 / 6H15/2 and 4F9/2 / 6H13/2 transitions, while the band at 664 nm corresponds to transition 4F9/2 / 6H11/2. These results, indicate that the co-doped (Dy3+): SiBBiTe glassy samples having emission in the white region and thus can use for white LEDs.