Femtosecond ligand/core dynamics of microwave-assisted synthesized silicon quantum dots in aqueous solution.

ABSTRACT: A microwave-assisted reaction has been developed to produce hydrogen-terminated silicon quantum dots (QDs). The Si QDs were passivated for water solubility via two different methods: hydrosilylation produced 3-aminopropenyl-terminated Si QDs, and a modified Stöber process produced silica-encapsulated Si QDs. Both methods produce water-soluble QDs with maximum emission at 414 nm, and after purification, the QDs exhibit intrinsic fluorescence quantum yield efficiencies of 15 and 23%, respectively. Even though the QDs have different surfaces, they exhibit nearly identical absorption and fluorescence spectra. Femtosecond transient absorption spectroscopy was used for temporal resolution of the photoexcited carrier dynamics between the QDs and ligand. The transient dynamics of the 3-aminopropen

SUBMITTER: Atkins TM 

PROVIDER: S-EPMC3377765 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature