Influence of silver nanoparticles concentration on spectroscopic characteristics of samarium doped zinc tellurite glass

Abstract

Tuning the enhanced optical properties of rare earth doped inorganic glasses by embedding metallic nanoparticles is ever-demanding in photonics. Optimized doping of NPs and subsequent detail characterizations for improved absorption and emission are the key issue. The effect of silver (Ag) nanoparticle on physical, structural and optical properties of Sm3+ doped zinc-sodium tellurite glass with composition 65TeO2-25ZnO-10Na2O-0.15 gramSm2O3-(y)AgCl, where y = 0, 0.003, 0.075, 0.12 and 0.18 gram are determined. Glass samples are prepared using melt quenching technique method and characterized by ultraviolet visible near infrared (UV-Vis-NIR) absorption spectroscopy, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffraction (XRD). XRD pattern confirms the amorphous nature of as-prepared glass. The incorporation of Ag NPs is evidenced to alter the structural arrangement and modifies the physical properties of glasses. The UV-Vis-NIR absorption spectra reveal six absorption peaks centered at 472 nm, 943 nm, 1089 nm, 1237 nm, 1392 nm, 1491 nm assigned to 6H5/2?4I11/2,6F11/2 , 6F9/2 , 6F7/2 , 6F5/2 , 6F3/2 transitions, respectively. TEM micrograph displays the uniform size distribution of silver nanoparticle with average diameter of ~7.9 nm. PL spectra exhibit two emission bands located at 599 nm and 643 nm due to 4G5/2?6H7/2 and 6H9/2 transitions, respectively. The observed enhancement in PL intensity is attributed to the highly localized electric field of Ag positioned in the vicinity of Sm3+ ion. Raman spectra shows the appearance of five peaks originates from 99.44 cm-1, 179.88 cm-1, 414.37 cm-1, 673.44 cm-1 and 768.66 cm-1 which corresponds to boson peak, network connectivity represents the Te2O7 and TeO4-4, stretching and bending Te-O-Te linkages, antisymmetric vibration of Teeq-Oax-Te linkages and stretching of NBO with adjacent Te atoms respectively. It is asserted that the amplification in Raman signal is initiated by the contribution of surface plasmon. The mechanism of enhancement is identified, analyzed and understood. The admirable features of our results are highly beneficial for solid-state laser and optical device fabrication.