Structural and spectroscopic properties of Eu3+ doped tellurite glass containing silver nanoparticles

Abstract

The growth of large silver nanoparticles in a tellurite glass of basic composition 70TeO2, 10Nb2O5, 20ZnO and doped with Eu3+ ions was evidenced by XRD and TEM measurements. Several experimental techniques were used to elucidate the nature of silver species and their effect on the luminescence of Eu3+ ions inside differently heat-treated glass samples. The analysis of the obtained results and the use of Judd-Ofelt theory have allowed us to suggest that the enhancement of Eu3+ ions is mainly due to an increase of the excitation rate of these ions induced by the local field enhancement via surface plasmon resonance (SPR) of silver nanoparticles and radiative energy transfer from small luminescent neutral silver clusters. On the other hand, the small emission quenching after long annealing time was attributed to back energy transfer from Eu3+ ions to silver species or to local field saturation.