Optical absorption and luminescence characteristics of Dy3+ doped Zinc Alumino Bismuth Borate glasses for lasing materials and white LEDs

Good optical quality Dy3+ doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by the conventional melt quenching technique and characterized by optical absorption and luminescence studies. The glassy nature of these materials has been confirmed through XRD measurements. From the absorption spectra, the three phenomenological JO parameters Ωλ (λ=2,4 and 6) have been determined from the absorption spectral intensities by using the JO theory. Luminescence spectra were measured for different concentrations of Dy3+ ions doped glasses by exciting the glasses at 387 nm. The intensity of Dy3+ emission spectra increases from 0.5 mol% to 1 mol % and beyond 1 mol % the concentration quenching is observed. The suitable concentration of Dy3+ ions for ZnAlBiB glassy material to act as good lasing material has been discussed by measuring the branching ratios and emission cross-sections for two strong emission transitions such as 4F9/2→6H15/2 and 4F9/2→6H13/2 observed in visible region. By exciting these glassy materials at various excitation wavelengths in n-UV region, the CIE chromaticity coordinates were evaluated for the two sharp emissions observed in blue (4F9/2→6H15/2) and yellow (4F9/2→6H13/2) regions to understand the suitability of these materials for white light generation.