Tel:
410-516-8145 Fax: 410-516-5293 materials-at-jhu.edu |
Department of Physics University of Maryland October 13, 2004
Carbon nanotubes - nanometer-diameter wires of pure carbon - have attracted significant interest both for the opportunity to explore the basic science of electrons in one dimension, as well as for their possible use in nanoelectronics applications. Carbon nanotubes may be metallic or semiconducting depending sensitively on how the graphene lattice is wrapped to form the tube. Research into the electronic properties of nanotubes has focused primarily on metallic nanotubes and their excellent conduction properties as ballistic quantum wires. Initial studies of semiconducting nanotubes showed poorer conduction, due to local conduction barriers - likely caused by defects in the nanotubes. Recent progress in nanotube growth has allowed the fabrication of very long (approaching one millimeter), very clean semiconducting nanotubes; the charge carrier mobility in these nanotubes exceeds 100,000 cm2/Vs at room temperature, higher than any other known semiconductor. In contrast to metallic nanotubes, these semiconducting nanotubes represent an electronically tunable one-dimensional system: the electronic mean-free-paths are tunable from sub-nanometers to microns by application of a gate voltage, corresponding to conductivity tunable from insulating to comparable to copper. I will discuss the use of these semiconducting nanotubes in exploring the basic physics of electrons in one dimension, and present some applications of these nanotubes to fabricate field-effect transistors and single-electron devices. Michael Fuhrer received his B.S. in Physics from the University of Texas at Austin in 1990. He received his Ph. D. in Physics from the University of California at Berkeley in 1998 after doing research on electronic and thermal transport in High-Tc and fullerene superconductors with Alex Zettl. Dr. Fuhrer remained at Berkeley as a postdoctoral researcher with Alex Zettl and Paul McEuen, working on electronic transport in carbon nanotube devices. Dr. Fuhrer joined the faculty at Maryland as an assistant professor in 2000. |
|
Are you considering a career
in Materials Science and Engineering? Click on the links below to learn more about
application options within our department. Prospective Undergraduates Prospective Graduates Prospective Part-Time Graduates |
| Department
of Materials Science and Engineering © 2004 Johns Hopkins University |