Enhanced Luminescence of Silver Nano-particles Doped Na2O-BaO-Borate Glasses

Abstract

Na2O-BaO-Borate glasses were synthesized with silver nano-particles of varying silver concentrations by the method of melt-quenching. Their densities of the glasses and hence molar volumes were computed. The existence of the silver nano-particles was depicted by characteristic band in the absorption spectra of UV- Visible studies known as plasmon band. Further the matrix also showed a small amount of nanostructures of the host which imparts the nonlinear behaviour. They were further visualized by the Scanning and Transmission electron microscopy. Optical band gap and Urbach energies were found. The band gap values change exactly in the opposite manner of density with silver doping. The wide luminescence band in the visible region formed for the excitation of plasmon band may be utilized for the luminescence enhancement of luminescent material like rare earth ions. The very significant result perceived from this is that the glass as such with silver nano-particles showed broad emission in the, green & blue portions of electromagnetic spectrum in the close vicinity of white light with the variation of silver content which can be utilized for the enrichment of the emission of lanthanide ions in the visible section of electro-magnetic spectrum.

Physical and optical traits of tellurite glass: effect of bimetallic TiO2/Au nanoparticles

“…Further, the addition of 0.03 mol% Au NPs (TZNETiAu0.03 glass) shows a slight decrement in the molar volume from 26.549 cm 3 .mol -1 to 26.434 cm 3 .mol -1 manifesting the reduction of the bond's length [8]. Initially, Au NPs occupy the interstitial and voids [12]. However, increasing the Au content from 0.05 mol% to 0.20 mol% elevates the molar volume from 26.440 cm 3 .mol -1 to 26.477 cm 3 .mol -1 reflecting the expansion in volume to accommodate a higher number of Au NPs and leads to the reduction in density [12].…”

“…Initially, Au NPs occupy the interstitial and voids [12]. However, increasing the Au content from 0.05 mol% to 0.20 mol% elevates the molar volume from 26.440 cm 3 .mol -1 to 26.477 cm 3 .mol -1 reflecting the expansion in volume to accommodate a higher number of Au NPs and leads to the reduction in density [12]. In another study, the expansion in the molar volume was associated with the generation of NBO that breaks the bond and uplifts the number of spaces in the network [13] that produce a less compact vitreous network [14].…”

“…The linear region of (ħ) 2 as a function of ħ and (ħ) 1/2 as a function of ħ were extrapolated to satisfy the condition of ħ at (ħ) 2 = 0 and (ħ) 1/2 = 0 to estimate the direct (E dir ) and indirect (E indir ) band gap energies [2]. Urbach energy (E U ) can be used to assess the degree of disorder which is defined by the UV-Visible absorption data of the absorption coefficient and the corresponding energy [12]. Figure 3d illustrates a plot of ln () versus photon energy to determine the Urbach energy.…”