Luminescence characterization of Eu3+ doped Zinc Alumino Bismuth Borate glasses for visible red emission applications

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Eu3+ ions have been prepared by rapid melt quenching technique and characterized for their luminescence behavior through various spectroscopic techniques such as absorption, excitation, emission, decay profiles and confocal image measurements at room temperature. From the measured absorption spectra, the bonding parameters (δ) were evaluated to find the nature of bonding between Eu3+ ions with its surrounding ligands in these ZnAlBiB glasses. The emission spectra of Eu3+ ions in ZnAlBiB glasses excited at 410 nm (CW laser) show the characteristic of Eu3+ ions with more intense visible red emission corresponding to 5D0→7F2 transition. This intense visible red emission is further confirmed by the confocal luminescence images recorded for all the ZnAlBiB glasses. Judd-Ofelt (J-O) parameters estimated from the emission spectral information are used to estimate the important radiative properties such as transition probability (AR), branching ratios (βR) and emission-cross sections for the prominent emission levels. The large stimulated emission cross-sections and branching ratios observed for ZnAlBiB glasses suggest the utility of these glasses in visible red region of the electromagnetic spectrum. The CIE chromaticity coordinates evaluated from the emission spectra and the confocal images recorded for all the ZnAlBiB glasses also indicates that, these glasses at higher concentration of Eu3+ ions are aptly suitable for intense red emission at 613 nm corresponding to 5D0→7F2 transition.