Semiconductor nanowires and nanotubes pdf

Two other important nanoscale objects are carbon nanotubes and quantum dots. It can also be defined as the ratio of the length to width being greater than. With a broad selection of compositions and band structures, these onedimensional semiconductor nanostructures are considered to be the critical components in a wide range of potential. Research in the field of semiconductor nanowires snws and nanotubes has been progressing into a mature subject with several highly interdisciplinary subareas such as nanoelectronics, nanophotonics, nanocomposites, biosensing, optoelectronics, and solar cells. A laser ablation method for the synthesis of crystalline. This approach was used to prepare bulk quantities of uniform singlecrystal silicon and germanium. Melting and welding semiconductor nanowires in nanotubes by yiying wu and peidong yang onedimensional nanostructures, such as nanowires and nanotubes, exhibit novel electronic and optical properties that are intrinsically associated with their low dimensionality and the quantum confinement effect. Onedimensional structures, such as carbon nanotubes and semiconductor nanowires, are currently of great interest due to their unique physical properties and potential applications, including nanoscale devices and sensors. The realtime melting and recrystallization behaviour of nanowires were monitored for germanium ge nanowires. Use in fabrication of nanowires, and nanotubes of polymers, metals, semiconductors. Besides singlewalled nanotubes, they also exist in doublewalled and multiwalled forms. Central to realizing applications through a bottomup paradigm is the rational. In recent years semiconductor nanowires and nanotubes have garnered increased attention for their unique properties. Singlecrystal metallic nanowires and metalsemiconductor.

Moreover, these nanomaterials demonstrate new and or enhanced functions crucial to many areas of technology. Our firstnano easytube process equipment is used worldwide for advanced research and development of semiconducting nanowires and nanotubes. Semiconductor nanowires nws and carbon nanotubes offer many opportunities for the assembly of nanoscale devices and arrays by the bottomup paradigm. Pdf carbon nanotubes, semiconductor nanowires and graphene.

In this process, laser ablation was used to prepare nanometerdiameter catalyst clusters that define the size of wires produced by vls growth. The capability of cutting, linking see cover, and welding see figure nanowires at relatively modest temperatures may provide a new approach to integrating. Different size or surfacetovolume ratio dependences were found for the ii. Carr, apl, 75, 920 1999 surface roughness induced losses. Aug 04, 2004 abstract semiconductor nanowires and nanotubes exhibit novel electronic and optical properties owing to their unique structural onedimensionality and possible quantum confinement effects in two dimensions. With their nanoscale dimensions comes high surface area and quantum confinement, promising enhancements in a wide range of applications. In the first chapters, some considerations concerning the preparation of metallic and semiconductor nanowires are presented. Semiconductor nanowires and nanotubes free download as pdf file. Pdf tipinduced charging of free standing semiconductor. Apr 11, 20 but unlike the precise manufacturing control that is possible with nanowires, so far methods for making nanotubes produce a random mix of types, which must be sorted to make use of one particular kind. Semiconductor nanowires nws represent a unique system for exploring phenomena at the nanoscale and are also expected to play a critical role in.

Plasmonassisted local temperature control to pattern. Berkeley in 2008, partly funded by an nsf igert fellowship in nanoscience and nanotechnology. A method combining laser ablation cluster formation and vaporliquidsolid vls growth was developed for the synthesis of semiconductor nanowires. Materials, synthesis, characterization and applications covers advanced materials for nanowires, the growth and synthesis of semiconductor nanowiresincluding methods such as solution growth, movpe, mbe, and selforganization. Semiconductor nanowires and nanotubes for energy conversion. Jan 24, 2012 the research into onedimensional semiconductor nanowires can be traced back to 1960s when wagner proposed the wellknown vaporliquidsolid vls growth model to explain silicon and germanium microwhiskers growth from metal islands with a feedstock of vapor source. Semiconductor nanowires promise to provide the building blocks for a new generation of nanoscale electronic and optoelectronic devices. The electronic properties of semiconductor sic, gan, bn, zno, zns, and cds nanowires and nanotubes were investigated using firstprinciples calculations based on density functional theory and generalized gradient approximation.

Semiconductor nanowires and nanotubes exhibit novel electronic and optical properties owing to their unique structural onedimensionality and possible quantum confinement effects in. Largearea blown bubble films of aligned nanowires and carbon. General synthesis of compound semiconductor nanowires. A carbon nanotube is a cylindrical structure that looks like a rolled up sheet of graphite. Therefore, the synthesis of onedimensional heterostruc tures is equally important for potential future applications including efficient lightemitting. Characterizing the properties of semiconductor nanowires is covered in chapters describing. Nanotubes and nanowires selected topics in electronics and. While nanowires and nanotubes diameters are negligible, their length can extend for hundreds of micrometers, even reaching lengths visible to the unaided eye. It is wellknown that nanotubes and nanowires with sharp tips are promising materials for applications as cold cathode field emission devices. For nanowire growth, the sapphire substrates were coated with a 1. Semiconductor nanowires and nanotubes exhibit novel electronic and optical properties owing to their unique structural onedimensionality and possible quantum confinement effects in two dimensions. With a broad selection of compositions and band structures, these onedimensional semiconductor nanostructures are considered to be the critical components in a wide range of potential nanoscale. With several points of view represented, including academic theoreticians, academic experimental device engineers, and industry researchers from wellknown semiconductor companies, nanotubes and nanowires is an essential source of reference for physicists, chemists, materials scientists, and graduate students interested in keeping abreast of.

Due to high surfacetovolume sv ratio, nanowires exhibit. Pdf semiconductor nanowires and nanotubes exhibit novel electronic and optical properties owing to their unique structural onedimensionality and. Onedimensional semiconducting nanowires allow for device engineering of next generation microelectromechanical systems mems and optoelectronic devices. He joined professor peidong yangs lab and received his ph. General synthesis of compound semiconductor nanowires by xiangfeng duan and charles m. Nanowires are just one exciting structure engineers and scientists are exploring at the nanoscale. Semiconductor nanowires for energy conversion chemical. The interfacedriven thermal instability of nanowires within nanotubes was reported. This volume is intended to orient the reader in the fast developing field of semiconductor nanowires, by providing a series of selfcontained monographs focusing on various nanowirerelated topics. The way in which nanotubes are formed is not exactly.

Nanowire fieldeffect sensors underlying detection using semiconductor nanowires is their configuration as fieldeffect transistors fets, which will exhibit a conductivity change in response to variations in the electric field or potential at the surface of the nanowire fet 5,40. Nanowires and carbon nanotubes nanowires are wires with a very small diameter, and can be used to build tiny transistors for processors. We have prepared aligned carbon nanotube bundles and yjunction nanotubes by the pyrolysis of appropriate organic precursors. Lieber the predictable synthesis of a broad range of multicomponent semiconductor nanowires has been accomplished using laserassisted catalytic growth. Tipinduced charging of free standing semiconductor nanowires and carbon nanotubes. By locally heating nanoscale metallic catalysts, growth of semiconductor nanowires and carbon nanotubes can be initiated and controlled at arbitrarily prespecified locations and down to the single nanostructure level in a roomtemperature chamber. Moreover, the equipment needed for this kind of vapor deposition is widely used in the semiconductor industry, and can easily be adapted for the production of nanowires. Melting and welding semiconductor nanowires in nanotubes wu. May 27, 2007 semiconductor nanowires nws and carbon nanotubes nts exhibit physical properties that make them attractive building blocks for many electronic and optical applications 1,2,3. Synthesis and characterization of nanotubes and nanowires constitute an important part of nanoscience since these materials are essential building units for several devices. Nanowires of binary group iiiv materials gaas, gap, inas, and inp, ternary. Significant melting point depression and large hysteresis during the meltingrecrystallization cycle are observed for semiconductor ge nanowires encapsulated within carbon nanotubes. Nanowire sensors for medicine and the life sciences. After that, some polymer nanowires single or complementing metallic nanowires are reported.

The aligned bundles are useful for field emission display while the yjunction nanotubes are. Nanowires, that is, 1d metal and semiconductor structures, have gained immense research interest due to their potential role in the miniaturization of modern electronic devices, for example, sensors with improved responses, and so forth. Melting and welding semiconductor nanowires in nanotubes. Semiconductor nanowires nws represent a unique system for exploring phenomena at the nanoscale and are also expected to play a critical role in future electronic and optoelectronic devices.

Alternatively, nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. Several families of nanostructures have been described over the past several decades, including quantum dots, 57,58 semiconductor nanowires, 5970 and carbon materials such as nanotubes and graphene, 7173 where each of these classes of materials has been shown to exhibit interesting properties. Singlecrystal metallic nanowires and metalsemiconductor nanowire heterostructures. A nanowire is a nanostructure, with the diameter of the order of a nanometer 10. Growth and surface properties of semiconductor and metal. Singlecrystal metallic nanowires and metalsemiconductor nanowire. These nanowires have been used for nanowire laser applications huang et al. Then, combinations of nanowires and carbon nanotubes are described and their properties connected with possible applications.