Luminescence of neodymium ion-activated magnesium zinc sulfophosphate glass: role of titanium nanoparticles sensitization

Abstract

A series of neodymium ion (Nd3+)-activated magnesium zinc sulfophosphate glasses sensitized with various contents of titanium nanoparticles (Ti NPs) were prepared via the melt-quenching method and characterized. The influence of Ti NPs on the optical characteristics of the glasses was determined. The XRD patterns of the as−quenched samples verified their amorphous nature. The differential thermal analyses (DTA) of the samples showed their good thermal stability against crystallization. The HRTEM image of the samples exhibited the formation of Ti3O5 NPs inside the amorphous network. The SPR bands of Ti3O5 NPs were probed at 587 nm and 730 nm. The ESR spectra of the glasses disclosed the existence of the singlet oxygen induced by the surface plasmon resonance (SPR) effect of Ti3O5 NPs. The absorption spectra of the glasses revealed twelve characteristic bands of Nd3+. The Judd-Ofelt calculations were performed to support the experimental spectroscopic results. The up−conversion (UC) photoluminescence (PL) emission spectra of the glasses revealed an intense yellow band at approximately 585 nm due to the 4G5/2 + 2G7/2 → 4I9/2 transition in Nd3+. The glass prepared with 0.4 mol% of Ti NPs displayed the highest PL intensity enhancement and maximum gain bandwidth. In short, the overall properties of the glasses were sensitive to the contents of Ti NPs. The observed improvement in the optical traits of the proposed glasses was attributed to the Ti NPs SPR-induced local field effect (LFE) in the proximity of Nd3+. Present findings could contribute to the development of the proposed glass-based solid−state laser and photonic devices.