Ligand Dynamics of Aqueous CdTe Nanocrystals at Room Temperature

On the basis of dilution and pH experiments, in this paper we demonstrated the possible ligand dynamics of aqueous CdTe nanocrystals (NCs) at room temperature. During storage, the excess ligands and cadmium−ligand compounds in solution were preferentially adsorbed on NC surface before they diffused into the ligand shell. Though the adsorption layer could not directly determine the photoluminescence (PL) property of NCs, it affected the diffusion process of free ligands and cadmium−ligand compounds into the ligand layer. The treatments of dilution, concentration, storage, and pH adjustment were believed to affect the thickness of adsorption layer and the diffusion behavior of ligands and hence brought different PL quantum yields.