Au-silica core/shell hybrid nanoparticles furnished with CdTe nanocrystals for enhanced plasmon-exciton interactions

Abstract

To date extensive research efforts have confirmed that optical properties of bulk semiconductors and metals are substantially modified when they are transformed into nano-dimensions. For example, metal nanoparticles with dimensions less than hundred nanometers strongly oscillate at a specific resonance frequency to generate localized surface plasmons depending on their size. This creates strongly localized electric fields in the close proximity of the metal nanoparticles under external excitation. Similarly, because of the size effect, semiconductor quantum dot nanocrystals (NCs), with dimensions less than 10 nanometers, feature highly tunable absorption and emission characteristics. High levels of brightness and photostability, and broad excitation range with sharp emission spectra make these NCs ideal candidates as active materials in light emitting diodes and solar cells, and as fluorescent labels in bioimaging. This paper presents the synthesis and characterization of a new set of CdTe NC decorated, Au-silica core/shell hybrid nanoparticles with silica shell thicknesses controlled and tuned by synthesis.This paper demonstrates that Au-silica core/shell nanoparticles can successfully assemble CdTe nanocrystals right on their silica shells for enhanced plasmon-exciton interactions, while avoiding the problems of lacking control in spacing and limited film thickness.