Portal:Nanotechnology

From Wikipedia, the free encyclopedia
  (Redirected from Wikipedia:NANO)
Jump to: navigation, search

edit

Welcome to the nanotechnology portal

Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometers.

Nanotechnology is very diverse, including extensions of conventional device physics, new approaches based on molecular self-assembly, developing new materials with nanoscale dimensions, and investigating whether we can directly control matter on the atomic scale. Nanotechnology entails the application of fields as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc.

There is much debate on the future implications of nanotechnology. Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials and energy production. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics, as well as speculation about various doomsday scenarios.

edit

A diagram of a wrap-around gate CNTFET, where the entire circumference of the nanotube is gated, which ideally improves the electrical performance of the CNTFET

Carbon nanotube field-effect transistor

Selected article

A carbon nanotube field-effect transistor (CNTFET) refers to a field-effect transistor that utilizes a single carbon nanotube or an array of carbon nanotubes as the channel material instead of bulk silicon in the traditional MOSFET structure. First demonstrated in 1998, there have been major developments in CNTFETs.

The exceptional electrical properties of carbon nanotubes arise from the unique electronic structure of graphene itself that can roll up and form a hollow cylinder. A carbon nanotube’s bandgap is directly affected by its chirality and diameter. If those properties can be controlled, CNTs would be a promising candidate for future nano-scale transistor devices. Moreover, because of the lack of boundaries in the perfect and hollow cylinder structure of CNTs, there is no boundary scattering. CNTs are also quasi-1D materials in which only forward scattering and back scattering are allowed, and elastic scattering mean free paths in carbon nanotubes are long, typically on the order of micrometers. As a result, quasi-ballistic transport can be observed in nanotubes at relatively long lengths and low fields. Because of the strong covalent carbon-carbon bonding in the sp2 configuration, carbon nanotubes are chemically inert and are able to transport large amounts of electric current. In theory, carbon nanotubes are also able to conduct heat nearly as well as diamond or sapphire, and because of their miniaturized dimensions, the CNTFET should switch reliably using much less power than a silicon-based device.

edit

Quantum dot

Selected image

Energy transfer diagrammed from nano-thin layers of Sandia-grown quantum wells to the LANL nanocrystals (a.k.a. quantum dots) above the nanolayers.
Credit: Los Alamos National Laboratory

Energy transfer diagrammed from nano-thin layers of Sandia-grown quantum wells to the LANL nanocrystals (a.k.a. quantum dots) above the nanolayers.

edit

Heinrich Rohrer

Heinrich Rohrer b. 1933

Selected biography

Heinrich Rohrer is a Swiss physicist who shared half of the 1986 Nobel Prize in Physics with Gerd Binnig for the design of the scanning tunneling microscope (STM) while at the IBM Zurich Research Laboratory. His earlier research had included studying length changes of superconductors at the magnetic-field-induced superconducting transition with Wolfgang Pauli, thermal conductivity of type-II superconductors and metals, magnetoresistance in pulsed magnetic fields, and nuclear magnetic resonance.

Articles

Categories

Associated Wikimedia

The nanotechnology portal updates once a week. See full schedule. Purge server cache