Growth of CdSe quantum rods and multipods seeded by noble-metal nanoparticles

The growth of CdSe quantum rods and multipods seeded by using noble-metal nanocrystals (NCs) was investigated. The colloidal growth of nonspherical NCs was achieved by the reaction carried out in the presence of two surfactants with different binding abilities to the NC faces such as phosphoric acid and a long-chain carboxylic acid or amine. The strongly adsorbed phosphoric acid slows the growth of the NC and results in growth along the c-axis of the wurtzite structure. A mixture of carboxylic acid and amine without a phosphoric acid did not induce anisotropic NC growth but yields spherical NCs. The method for anisotropic crystal growth used metallic nanoparticles as seeds for the melting of precursor atoms and crystal growth occurred at the metal's liquefied surface. The noble-metal nanoparticles can seed anisotropic growth of high quality CdSe NCs at lower temperature and reagent concentrations.