Photoluminescence characteristics of Eu2O3 doped calcium fluoroborate glasses

The present work reports the preparation and characterization of calcium fluoroborate (CFB) glasses doped with different concentrations of Eu2O3. The spectroscopic free-ion parameters are evaluated from the experimentally observed energy levels of Eu3+ ions in CFB glasses by using the free-ion Hamiltonian model (H-FI). The phenomenological Judd-Ofelt (J-O) parameters, Omega(2), Omega(4) and Omega(6), are evaluated from the intensities of Eu3+ ion absorption bands by various constraints. From these J-O parameters (Omega(lambda)), the radiative parameters such as transition probabilities (A(R)), branching ratios (beta(R)), stimulated emission cross sections (sigma(e)) and radiative lifetimes (tau(R)) are evaluated for D-5(0) -> F-7(J) (J = 0-6) transitions. From the decay curves of D-5(0) emission level, the experimental lifetimes (tau(exp)) are obtained for different Eu3+ ion concentrations. The variation of emission intensities and experimental lifetimes with concentration is analyzed/discussed to optimize the Eu2O3 concentration in CFBEu glasses for device applications. (C) 2012 Elsevier B.V. All rights reserved.