Spectroscopic investigation on Dy3+ ions in borate glasses for photonic applications

Abstract

The samples were prepared and characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), optical absorption, photoluminescence (PL), and decay time measurements on borate-based glasses with compositions of (60-Y) B 2 O 3 ? 20 CaO ? 20 NaF ? Y Dy 2 O 3 (Y = 0.2, 0.4, 0.6, 0.8, and 1.0%). Using the JO theory, the Judd-Ofelt (JO) intensity parameters (X k , k = 2, 4, and 6) for BCNFDy glasses were computed. The emission bands have been used to determine the chromaticity color coordinates (x, y), yellow to blue (Y/B) intensity ratios, stimulated emission cross-sections (r(k p )), effective band widths (Dk eff ), and others. By observing the strong 4 F 9/2 ? 6 H 15/2 transition (486 nm), the decays from the Dy 3? ions 4 F 9/2 level have been calculated. Due to the quenching process, it is discovered that the experimental lifetimes (s exp ) shorten as the quantity of Dy 3? ions increases. At lesser concentrations, the lifetime curves are absolutely single exponential and they step by step change to nonexponential at larger Dy 3? ion concentrations. A dipole-dipole type of energy transmission between the donor and acceptor is shown by how well the Inokuti-Hirayama (IH) model matches the non-exponential decay time curves for S = 6. The results obtained point to the usefulness of the glasses for possible future applications in w-LED technology.