Luminescence behaviour and phonon sideband analysis of europium doped Bi2O3 based phosphate glasses for red emitting device applications

Abstract

0.5 mol% of europium (Eu3+) doped bismuth phosphate glasses (BiP) with different contents (0, 5, 10 and 15 mol%) of bismuth and different (0.1, 0.3, 0.5, 1.0, 1.5 and 2.0) mol% of Eu3+ doped 5 mol% bismuth contained BiP glasses were made by melt-quenching technique. The structural and photoluminescence properties were analysed via FT-Raman, excitation, luminescence and decay time computations. Judd-Ofelt (J-O) parameters were evaluated from the emission spectra and also various radiative properties such as radiative transition probabilities (AR), radiative lifetimes (τrad), stimulated emission cross-sections (σe), branching ratios (β), optical gain bandwidths (σexΔλeff) and optical gain (σexτrad) values for the observed emission transitions are studied. The electron-phonon coupling constants (g), phonon energies (hω) and the multiphonon relaxation rates (WMPR) were determined. The decay curves of 5D0 level of Eu3+ in all the studied glasses exhibit single exponential nature. The lifetimes are obtained from the decay curves and reported. The CIE chromaticity co-ordinates were computed and they have fallen in red region. The characteristic red luminescence emission around 612 nm for 5D0→7F2 transition confirmed that the Eu3+ doped BiP glasses might be useful to fabricate red lasers and display devices.