Spectral properties of Eu3+ : ZnO-B2O3-SiO2 glasses

Studies on the vibronic spectral analysis of Eu3+ ions doped in zinc borosilicate glass have been performed in order to correlate them with the local environment of the dopant ion in this host matrix on the basis of the Fourier Transform infrared (FT-IR) spectroscopy. It is noticed that the Eu3+ ions are bonded to the bridging and non-bridging oxygens of BO3, BO4 and SiO4 Structural units. The Stark splittings exhibited especially by the emission transitions: D-0 -> F-7(1), D-5(0) -> F-7(2) and their intensity ratio (EMIR) could indicate that the Eu3+ ions are taking the sites, which lack inversion symmetry. Judd-Ofelt intensity (12, angstrom = 2, 4, 6) parameters have been obtained from the measured absorption spectra of Eu3+: Zinc borosilicate glass and these intensity defining factors are used in the computation of the emission transition probabilities, radiative rates, braching ratios and radiative lifetimes of the fluorescence transitions. Decay curves of the emission transitions ((5)Do -> F-7(0,1,2,3,4)) were measured and their lifetimes have been estimated. Besides this, Optical band gap energies (E-Opt) have also been evaluated from the base glass absorption spectrum and the values are found to be 4.82 and 4.60 eV for direct and indirect band gaps, respectively. (c) 2005 Elsevier B.V. All rights reserved.