The structural and luminescence properties of strontium borotellurite glass doped with europium and dysprosium

Abstract

A series of strontium borotellurite glasses with the general formula xSrO·(100-x)[0.5B2O3·0.5TeO2], (15 = x = 35 mol%) have been prepared. In addition, glass samples with the composition 20SrO·40B2O3·40TeO2 and 30SrO·35B2O3·35TeO2 doped with Europium, Eu3+ and Dysprosium, Dy3+, (1 mol% each) were also prepared. All the glass samples were prepared using melt quenching method, followed by annealing process at 400 oC for 6 hours. The structural property of the glass samples was characterized using X-ray diffractometer (XRD) and Fourier transform infrared spectrometer and the luminescence property using fluorescence spectrometer. The XRD diffraction patterns showed the amorphous phase of the glass sample. Infrared spectra reveals that increased of strontium in borotellurite glass significantly promote conversion of [BO3] to [BO4] and [TeO4] to [TeO3] in the structural units. This conversion indicated some disintegration of boroxol rings into network structures while strontium acted as network modifier. The emission spectra line of undoped and doped glasses is in the visible range. The emission spectra line of undoped glass at 513 nm originated from the glass host. The emission spectra lines from Eu3+ doped glass are due to transition of Eu3+ ion at 5D0?7F0 (580 nm), 5D0?7F1 (593 nm), 5D0?7F2 (613 nm) and 5D0?7F3 (652 nm). Meanwhile the emission spectra lines from Dy3+ doped glass are due to transition from 4F9/2?6H15/2 (483 nm), 4F9/2?6H13/2 (578 nm) and 4F9/2?6H11/2 (660 nm). The emission spectra lines from Eu3+ and Dy3+ doped glass are shown at 483 nm, 513 nm, 578 nm, 613 nm and 660 nm. The results revealed that the emission intensity of Eu3+ and Dy3+ doped glass are dependent on host composition. Furthermore, the luminescence decay curve for Eu3+ doped glass showed multi-exponential decay with lifetimes for 20SBT:1Eu3+ glass are 1 ns and 22 ns, while for 30SBT:1Eu3+ glass, the lifetimes are 1 ns and 18 ns.