Physical, structural and luminescence investigation of Eu³⁺-doped lithium-gadolinium bismuth-borate glasses for LEDs

The aim of the current report is to fabricate Eu³⁺-doped glasses with the chemical composition of 50Li₂O-15Gd₂O₃-5Bi₂O₃-(30-x)B₂O₃-xEu₂O₃ (where x = 0.5, 1.0, 1.5, 2.0 and 2.5 mol%), with the help of conventional melt quenching technique. The fabricated glasses have been studied with help of physical, structural and luminescence properties for application of LEDs. The structural properties were investigated by XRD and FTIR spectra. Physical properties have been measured. Direct and indirect optical energy band gap (E_g) have been calculated and found to be increasing with Eu₂O₃ concentration. Luminescence spectra have been observed from photo and radioluminescence spectra and found in good agreement with each other, however the concentration quenching was not determined for the samples. The high-covalence and asymmetric nature was confirmed from Photoluminescence emission and RL emission transition as well as from the higher values of luminescence intensity ratio. The JO parameters have been found for the better performance of lasing materials. The lifetime's data have been found to be decreasing from 1.64 to 1.50 ms, which is the confirmation of energy transfer in Eu³⁺ ions through cross relaxations. From the calculated properties it has been suggested that the present glass samples might be good for red-light emitting devices.