SYNTHESIS OF Pb ALLOY AND CORE/SHELL NANOWIRES
Semiconductor nanowires (NWs) possess unique optical and electrical properties due to their anisotropic shape as well as their size-tunable electronic structure. In this chapter, we discuss the solution phase synthesis of II–VI and IV–VI semiconductor nanowires (e.g. ZnSe, CdS, CdSe, CdTe, PbS, PbSe, and PbSexS1−x) as well as NW-based heterostructures involving core/shell and metal nanoparticle-decorated morphologies. We subsequently discuss the application of these materials within the context of nanowire yarns, nanowire-functionalized cotton textiles, and renewable energy applications involving nanostructured solar cells and photocatalytic hydrogen generation.
using the Lithographically Patterned Nanowire Electrodeposition ..
The significant reductions in thermal conductivityachieved using lead chalcogenide and In2-xGaxO3(ZnO) n nanowireshighlight their use in thermoelectric power generation.
This directelectrical field control of the electrical conductivity and Seebeckcoefficient suggests a powerful strategy for optimizing ZT inthermoelectric devices and these results represent the firstdemonstration of field-effect modulation of the thermoelectric figure ofmerit in a single semiconductor nanowire.
Rapid synthesis of aligned zinc oxide nanowires - …
Rational design and synthesis of nanoscale materials is critical to work directed towards understanding fundamental properties, creating nanostructured materials, and developing nanotechnologies. One-dimensional (1D) nanostructures [such as nanowire (NW) and nanotubes] have been the focus of considerable interest because they have the potential to answer fundamental questions about role of dimensionality in physical properties and are expected to play a central role in applications ranging from molecular electronics to scanning probe microscopy probes. To explore the diverse and exciting opportunities in 1D system requires materials for which the chemical composition, diameter, length, electronic, and optical properties can be controlled and systematically varied. To meet these requirements, we have focused our efforts on developing a general and predictive approach for the synthesis of 1D structures, much as molecular beam epitaxy has served as an all-purpose method for the growth of two-dimensional (2D) structures. Specifically, it is important to achieve the ability to design and synthesize rationally NWs with predictable control over the key structural, chemical and physical properties, since such control would greatly facilitate studies designed to understand the intrinsic behavior of 1D structures and to explore them as building blocks for nanoscale electronics. Here, in this article, we review recent advances in rational synthesis of semiconductor NWs. We will first address the key requirement for 1D growth and give a brief overview of various methods towards 1D materials. Subsequently, we will focus our discussion on growth of a broad range of semiconductor NWs via a metal-nanocluster mediated catalytic growth method based on vapor-liquid-solid (VLS) growth mechanism. Next, we further describe growth of NW materials with controlled physical size including diameter and length. Lastly, we discuss growth of NW heterostructures and superlattices with composition/doping modulation along the axial or radial direction.
Rapid synthesis of aligned zinc oxide nanowires
Compared to the bulk, the PbSe nanowires exhibited asimilar Seebeck coefficient and a significant reduction in thermalconductivity in the temperature range 20 K to 300 K.
Branched nanowires: Synthesis and energy applications
The ligand-control methodology has shown some impressive examples of ultrathin nanowires, but a common trait in most of those reactions is the inability to gradually tune the diameter of the nanowire. The occurrence of material-specific ‘‘magic’’ diameters still has to be experimentally validated in those samples, but it is consistent with most theoretical investigations of ultrathin semiconductor and metallic nanowires. Such a mechanism would also explain how ligands could completely stop the growth along two directions, which is generally not the case for bulkier nanostructures. More research is necessary to further develop our understanding on this issue.