UM physicists show nanotubes are best semiconductors.University of Maryland University of Maryland can refer to:
A team of researchers led by Michael Fuhrer füh·rer also fueh·rer n. A leader, especially one exercising the powers of a tyrant. [German, from Middle High German vüerer, from vüeren, to lead, from Old High German , assistant professor of physics at the UM's Center for Superconductivity superconductivity, abnormally high electrical conductivity of certain substances. The phenomenon was discovered in 1911 by Kamerlingh Onnes, who found that the resistance of mercury dropped suddenly to zero at a temperature of about 4.2°K;. Research, has fabricated a semiconducting nanotube A carbon molecule that resembles a cylinder made out of chicken wire one to two nanometers in diameter by any number of millimeters in length. Accidentally discovered by a Japanese researcher at NEC in 1990 while making Buckyballs, they have potential use in many applications. transistor that shows a mobility almost 25% higher than any previous semiconducting material and more than 70 times higher than the mobility of the silicon used in today's computer chips. The results, published online in the journal Nano Letters, provide new evidence that semiconducting carbon nanotubes hold great promise for replacing conventional semiconductor materials Semiconductor materials are insulators at absolute zero temperature that conduct electricity in a limited way at room temperature (see also Semiconductor). The defining property of a semiconductor material is that it can be doped with impurities that alter its electronic properties in applications ranging from computer chips to biochemical sensors. The International Technology Roadmap for Semiconductors The International Technology Roadmap for Semiconductors is a set of documents produced by a group of semiconductor industry experts. These experts are representative of the sponsoring organisations which include the Semiconductor Industry Associations of the US, Europe, Japan, says that a replacement material for silicon with higher mobility will be necessary by the year 2010. According to Fuhrer, his new findings indicate nanotubes could fill that role. "Many challenges remain before nanotubes can be used instead of silicon in computer chips," said Fuhrer. "The contact resistance between nanotube and metal electrodes must be controlled. Nanotube batches must be prepared that contain only semiconducting nanotubes. And nanotubes must be placed with precision on substrates." However, according to Fuhrer, significant progress is taking place in these areas and the challenges do not seem insurmountable. |
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