Zinc Chalcogenide Seed-Mediated Synthesis of CdSe Nanocrystals: Nails, Chesses and Tetrahedrons

Systematically shape-controlled synthesis of colloidal semiconductor nanocrystals (NCs) has attracted increasing attention recently for both fundamental and technological interest. The study on the synthesis of colloidal CdSe NCs has given rise to well-developed methods for producing diverse shapes such as rods, wires, cubs and discs. In the current study, we demonstrate the shape evolution of CdSe NCs by using a seed-mediated approach by control reaction temperature and injection methods. The synthesis utilizes small (2.0-3.0 nm) zinc chalcogenide NCs with zincblende structure as seeds for subsequent growth, which results in distinct shapes of nail-shaped, tetrahedron-shaped, chess piece-shaped, and Y-shaped CdSe NCs with high yield and good uniformity. The morphologies and crystal structures of the prepared CdSe NCs were well characterized by transmission electron microscopy (TEM), high resolution TEM, and X-ray diffraction measurements. This wide variation of shapes provides important information on the growth of CdSe NCs and promotes the shape-controlled synthesis of other NCs by seed-mediated synthetic method.