Afterglow Properties of Silica-Capped Sr2MgSi2O7:Eu,Dy Nanoparticles Prepared by Laser Ablation in Ethanol

Abstract

The effect of silica-capping on the afterglow property of Sr 2 MgSi 2 O 7 :Eu,Dy nanoparticles was investigated. Sr 2 MgSi 2 O 7 :Eu,Dy nanoparticles were prepared by laser ablation in liquid. Afterglow nanoparticles were capped with silica using Stöber method. A dense silica capping layer was achieved after 4 hours of reaction. Silica-capping of the afterglow nanoparticles improved the particles' afterglow property, which was degraded by nanosizing. Decay curves indicated that initial values of afterglow intensity were increased with silica-capping capacity. Moreover, silica-capping decreased the decay curve constant γ, which was related to trap parameters. The decrease in the value of γ resulted in the reduction in the slope of decay curve, and thus the improvement of the afterglow property. We concluded that capping nanoparticles with silica improved the particles' afterglow property by the passivation of surface defects and the prevention of energy transfer to water molecules.

Laser Synthesis and Processing of Colloids: Fundamentals and Applications

“…Coated on commercial overhead transparency films, LSPC-synthesized YAG:Ce nanophosphors show better transmittance (90% vs 82%) than commercial YAG:Ce phosphors and limited backscattering effect (44%) . Water-insoluble long-afterglow NPs (e.g., Sr 2 MgSi 2 O 7 :Eu 2+ ,Dy 3+ ) synthesized by LAL are another interesting group of luminescent nanophosphors for lighting devices because they allow prolonged emission after switching off the excitation light. , Among all of the doped luminescent particles, upconverting NPs with anti-Stokes upconversion (high-energy photons generation via low-energy photons’ absorption) luminescent emission are particularly attractive for bioimaging, volumetric displays, and photonics applications . Direct synthesis of Y 2 O 3 :Er,Yb upconverting NPs by LAL and their dispersibility control by silane coupling and PEG conjugation have been presented by the Wada group.…”