Silver nanoparticles enhanced luminescence of Eu3+-doped tellurite glass

A series of silver nanoparticles (NPs) embedded zinc-tellurite glass is prepared by the melt-quench method. In order to nucleate and reduce the silver ions (Ag+) to silver NPs (Ag0) heat treatment with different time intervals above the glass transition temperature is carried out. The transmission electron microscopy (TEM), differential thermal analyses (DTA), UV-vis-NIR absorption spectroscopy and photoluminescence (PL) spectroscopy are used to study the annealing time dependent optical properties. The glass transition temperature (Tg) from DTA for an as prepared sample is 296 °C. TEM image displays the homogeneous distribution of silver NPs with average diameter ~8 to 27 nm. From UV-vis-NIR spectra, the observed localized surface plasmon resonance (LSPR) bands are found to be located within the range 487-501 nm for the samples with AgCl. Furthermore, under an excitation of 395 nm, four bands are observed at 585, 612, 650, 698 nm which corresponds to the 5D0-7F0;1;2;3;4 transitions of Eu3+ ions. Moreover, luminescence intensity of all the bands is increased due to the presence of silver nanostructures. The hypersensitive transition 5D0-7F2 of Eu3+ is much more enhanced (~1.9 times) mainly due to the local field effect of silver NPs.