Optical and plasmonic properties of Er3+ and silver co-doped borate nano-composite glasses

The erbium and silver co-doped sodium and barium modified borate glasses were synthesized by the traditional melt quenching practice. The non-crystalline molecular arrangement of the glasses was substantiated by the x-ray diffraction. The density of the glasses measured increased with the rare earth concentration and the values found to be in the range of 2.815-2.959 g cm−3. The molecular vibrations were understood by the technique of Fourier transform IR spectroscopy. The creation of silver nanoparticles was figured out by the surface plasmon band in the UV-Visible absorption spectra. The values of direct and indirect optical band gaps calculated were in the range of (3.46-3.72) eV and (3.10-3.32) eV. The silver doped glasses after heat treatment showed the increased size of the nanoparticles, which is established by the scanning electron microscopy and the transmission electron microscopy. From surface area enhanced diffraction, silver nanoparticles and nanowires of matrix were indexed. The luminescence enhancement of the erbium ion was attributed to the plasmon resonance of the silver nanoparticles. For higher rare earth doping, the quenching of the luminescence was observed. These photonic glasses showed emission in the blue, green and green and yellow region of the visible spectrum for the different energy excitation wave lengths 378, 488 and 521 nm respectively.