(546a) Media Effect on Cdte Nanowire Growth: Mechanism of Self-Assembly, Ostwald Ripening, and Control of Nw Geometry

The spontaneous self-assembly of II-IV stabilizer depleted nanoparticles (NPs) into nanowires (NWs) is a complex process that is only partially understood. This paper examines the mechanism governing the change in growth pattern of CdTe NWs induced by the addition of dimethyl sulfoxide (DMSO) to the NW growth solution. We propose that after the initial step of formation of NP pearl necklace assemblies, the recrystallization of these assemblies and their subsequent growth into long NWs involves Ostwald ripening. Addition of DMSO allows for improved control over the NW length and diameter. As the DMSO concentration in the NW growth solution is increased, the resulting NW length and diameter increases. When DMSO concentrations are raised above 70%, there is no NW formation, which is attributed to inhibition of the formation of pearl necklace assemblies. DMSO influence on NW morphology can be correlated with the effect of the added organic solvent on electrostatic interactions between the nanoparticles and mass exchange between the growing nuclei.