Recent advances in the shape control of inorganic nano-building blocks

Inorganic nanocrystals with certain geometries exhibit unique shape dependent phenomena and subsequent utilization of them as building blocks for the key components of nanodevices is of huge interest. Architecture of these nanocrystals can be simply classified by their dimensionalities: zero-dimensional (0D) quantum dots including spheres, cubes, and tetrahedrons, one-dimensional nanorods and wires, two-dimensional (2D) nanodiscs and plates, and other advanced shapes such as rod-based multipods and nanostars. Among them, one-dimensional (1D) structures are of current interest in materials chemistry not only because they exhibit novel optical properties arising from dimensional anisotropy, but also because they can be utilized as key materials in addressable two-terminal circuits for nanodevice applications. We describe here the current studies on a variety of one-dimensional semiconductor and metal oxide nano-building blocks obtained by liquid phase colloidal synthetic methods. Several mechanisms and critical parameters for nanocrystal shape guiding processes are carefully examined. Once we understand the guiding laws of nanocrystals growth, many new nano-building blocks will easily be tailored for the discovery of novel phenomena and also further exciting advancement of nanoscience and nanotechnology. (c) 2004 Elsevier B.V. All rights reserved.