Visible fluorescence characteristics of Dy3+ doped zinc alumino bismuth borate glasses for optoelectronic devices

Zinc Alumino Bismuth borate (ZnAlBiB) optical glasses of different compositions doped with 1 mol% of Dy3+ ions were prepared by the conventional melt quenching technique and investigated by the XRD, optical absorption, photoluminescence and decay curve analysis. The glassy nature of ZnAlBiB host has been confirmed through XRD measurements. From the absorption spectral measurements, the three phenomenological intensity parameters Ωλ (λ=2,4 and 6) have been determined from the Judd–Ofelt (J–O) theory. By using JO intensity parameters, several radiative properties such as transition probability (AR), branching ratio (βR) and radiative lifetimes (τR) have been determined. The room temperature photoluminescence spectra of Dy3+ ions doped ZnAlBiB glasses gave two relatively intense emission bands 4F9/2→6H15/2 (blue), 4F9/2→6H13/2 (yellow) along with one faint band. The higher values of branching ratios and stimulated emission cross-sections for the 4F9/2→6H13/2 transition suggest the utility of these glasses as potential laser materials. The decay curves have been recorded for all the ZnAlBiB glasses to measure the quantum efficiency of these glasses by measuring the experimental lifetime (τexp). The radiative properties and CIE chromaticity co-ordinates have been evaluated from the emission spectra to understand the feasibility of these glasses for optoelectronic devices.