Photoluminescence of silver in glassy matrices

Abstract

This work studies the behavior of Ag + ions incorporated in different silica-based glassy matrices. To this end, Ag-doped silica coatings, prepared via sol-gel and deposited on pure silica and soda-lime glasses, are investigated by means of structural and optical spectroscopy techniques. Silver tends to segregate towards the interface during the annealing process, but in the case of soda-lime glassy substrates the exchange process favors its diffusion into the substrate. The environment of Ag + ions during the annealing process determines their final oxidation state. In the pure silica matrix, Ag + ions are found to be unstable and tend to reduce to Ag 0 , with the subsequent formation of metallic nanoparticles. However, the presence of network formers and modifiers gives rise to the appearance of nonbridging oxygen, which allows the stabilization of Ag + ions in the matrix.

Kinetics of Ag nanoparticle growth in thick SiO2 films: An in situ optical assessment of Ostwald ripening

“…The observed SPR peak red shift is related to variation in the local dielectric constant around the NPs in the matrix in relation to the physico-chemical consequences of O 2 diffusion [11,12]. Herein, it should be taken into account that during HT in air, metal oxidation and the consequent exchange between Ag þ ions in the film and Na þ ions in the soda glass substrate are supported [12,15,16]. Thus, besides possible film densification, such sodium doping of the film by the substrate is a likely cause for the variation in SPR peak position observed, since this process is also expected to influence film refractive index [17].…”

Facile deposition and plasmonic resonance of Ag–Au nanoparticles in titania thin film

“…[22][23][24][25] The first emissions in both the film at 405 and 384 nm are attributed to the near band edge transition and direct transition from the conduction band to the valence band of TiO 2 . [22][23][24][25] The first emissions in both the film at 405 and 384 nm are attributed to the near band edge transition and direct transition from the conduction band to the valence band of TiO 2 .…”

“…16 An additional impure Ti 4 O 7 phase was observed in ''Ag-Au-TiO 2 film'', which was removed after annealing the sample at 600 1C in an inert atmosphere. [14][15][16][17][18][19][20][21][22][23][24][25] The main FTIR peak positions are mentioned in Table S2 of the ESI. This implies that after annealing, the deposited Au nanoparticles entered into the vacant sites of either anatase TiO 2 or rutile TiO 2 .…”

Thermal studies of soda glass metal nanocomposite synthesized by ion exchange

“…The absorption intensity increases significantly, while the width of the absorption band reduces systematically with the annealing temperatures [ Figure 1 curves (d, e, f)], indicating an increase in volume fraction of silver nanoparticles in the soda glass matrix. Moreover, the colour of the transparent soda glass samples changes from colorless to yellowish at 500 o C which is a characteristic of Ag-cluster formation [14]. Figure 2 presents the photoluminescence spectra of the silver exchanged soda glass samples annealed at different temperatures.…”