Monolayer-Functionalized CdTe Nanocrystals with Controlled Fluorescent Properties Based on Chemical Surface Modification

Abstract

The significant enhancement of fluorescent quantum yields for CdTe nanocrystals (from 1 to 60 %) through chemical surface modifications is described, enabling us to synthesize monolayer-functionalized nanocrystals with controlled flurescent properties. Several detailed structural characterization for the purified nanocrystals upon reaction revealed that the process relies on the surface chemical attachment of thiolate ligands on the nanocrystal surface, probably with a defect site at the nanocrystal surface being compensated, allowing an increase in the probability of radiative recombination of excitons generated in the nanocrystals. The surface of the obtained nanocrystals could be further modified with other type of molecules through ligand exchange reaction without significant changes in structural and optical characteristics of the nanocrystals.