Structural and luminescence investigations of Gd3+ - Er3+ doped in lithium aluminum borate glasses using XANES and EXAFS techniques

The typical melt quenching technique was utilized to produce a possibly unique series of Gd3+ and Er3+ dual doped borate glasses with a composition of 25Li2O–5Al2O3-XGd2O3-(69.0-X)B2O3-1.0Er2O3. The amorphous nature and information on chemical bindings of the materials were validated by using fundamental characterization techniques such as X-ray diffraction, Fourier transform infrared, X-ray absorption near-edge structure, and optical screening to identify their features (absorption, excitation, and emission). The refractive index of the glasses improves from 1.5487 to 1.628 as the concentration of Gd2O3 increases. The optical absorption spectra of Er3+ doped glasses were measured from the ultraviolet (UV) through the visible (Vis) and near infrared (NIR) ranges with varying Gd2O3 concentrations in order to determine their optical properties. This luminescence was found to be predominant in photoluminescence spectra, which were obtained at an optimum doping Gd2O3 concentration of 7.5 mol%. The impact of Er3+ doping was assessed through photoluminescence, which exhibited a broad, intense NIR band at 1537 nm ascribed to the 4I13/2 → 4I15/2 transition of Er3+ ions at λEx = 486, 526, 651, and 978 nm excitation, which exhibits outstanding increased intensity with the Er3+ concentration until it reaches 1.0 mol %. A look at visible and near-infrared optical, it is observed that LAGd7.5BEr1.0 glass is a more potential candidate for photonic devices.