Structural and luminescence characteristics of thermally stable Dy3+ doped oxyfluoride strontium zinc borosilicate glasses for photonic device applications

Abstract

Structural, thermal, and photoluminescence (PL) characteristics of a series of Dy3+ doped Oxyfluoride Strontium Zinc Borosilicate (OFSZBS) glasses have been investigated. The XRD of 1.0 mol% Dy3+ ions doped OFSZBS glass and FT-IR investigations conducted on an un-doped as well as all the Dy3+ ions doped OFSZBS glasses confirm the non-crystalline nature and distinct functional groups present in it respectively. The Differential Scanning Calorimetry (DSC) thermogram recorded for an un-doped OFSZBS glass reveals thermal stability (ΔT) and transition temperature (Tg). The optical band gaps were computed using the Tau'c method. Under 348 nm pumping wavelengths, the Photoluminescence (PL) spectra of the as-synthesized OFSZBSDy glass samples exhibit blue (450 nm), yellow (575 nm), and red (650 nm) color transitions. The PL intensity increases with Dy3+ ions concentration up to 1 mol% and after that intensity decreases due to the concentration quenching effect. The PL decay profiles reported at higher concentrations were best fitted to the Inokuti-Hirayama (I-H) model for s = 6, indicating the energy transfer process as dipole–dipole in nature. The result obtained from the I-H model is in consonance with that of Dexter's theory. At 448 K, the PL intensity is up to 85% of room temperature, indicating that the as-synthesized glasses have exceptional thermal stability. Relatively higher values of quantum efficiency (η), emission cross-sectional area (σse), and probability of radiative transition (AR) observed for 1 mol% Dy3+ ions doped OFSZBS glasses declare their suitability in photonic devices under n-UV/blue pumping wavelength.