Tuneable and Au-enhanced yellow emission in Dy3Â +/Au co-doped antimony oxide glass nanocomposites

Dy3 +/Au co-doped antimony oxide glass nanocomposites were prepared in a glass matrix, having molar composition of 15K2O-15B2O3-60Sb2O3-10ZnO by single-step melt-quenching technique. Au nanoparticles (NPs) are generated in-situ by thermochemical reduction of Sb3 +. X-ray Diffraction (XRD) and Transmission Electron Microscopy confirm the presence of Au NPs in the samples. UV-Visible absorption spectra show the surface plasmon resonance (SPR) band of Au around 620 nm. When excited at 447 nm, all the nanocomposites exhibit visible yellow emissions yielding maximum with the sample containing 0.006 wt% Au. This sample is heat treated at 300 °C for different durations. XRD reveals that crystallization of the glassy matrix initiates after 5 h heat treatment. The SPR band of Au gets progressively widespread with increasing heat treatment duration due to rapid rate of Au NP generation at elevated temperature. Variation of photoluminescence (PL) intensity with heat treatment duration exhibits two maxima. The first one is due to attainment of critical size of NPs, for which emission becomes maximum. The second one is the effect of matrix crystallization, which reduces the phonon energy of the system and enhances PL intensity by reducing non-radiative loss. This enhancement and tuning of photoluminescence is very promising for various photonic applications.