Microwave Synthesis of Highly Aligned Ultra Narrow Semiconductor Rods and Wires

One dimensional nanostructures (rods, wires, tubes, ribbons) have recently attracted considerable attention. These nanostructures represent ideal systems for dimension dependent optical, electrical and mechanical properties, and are expected to play an important role as building blocks in devices and processes such as light-emitting diodes, solar cells, single electron transistors, lasers and biological labels.1,2 Many modern methods based on physical and chemical approaches have been developed for the synthesis of controlled size and shape of one dimensional nanostructures including, for example, vapor-liquid-solid and the solution-liquid-solid processes, solvothermal, template-assisted, kinetic growth control, self-assembly, and thermolysis of single-source precursor in ligating solvents.3 In addition to these methods, microwave irradiation (MWI) offers great advantges as the simplest and fastest procedure since selective dielectric heating, due to the difference in the solvent and reactant dielectric constants, can provide significant enhancement in reaction rates. Furthermore, MWI methods are unique in providing scaled-up processes without suffering thermal gradient effects, thus leading to a potentially industrially important advancement in the large-scale synthesis of nanomaterials. Although MWI methods have been demonstrated for the synthesis of a variety of high quality, nearly monodisperse semiconductor nanoparticles4, there are very few reports on the synthesis of one-dimensional semiconductors by MWI.3j-k,4 However, all the reported one-dimensional semiconductor nanostructures are wider than the Bohr radius, which limits the expected quantum confinement effects.
Full Story