Quick and Easy Enrichment of Metallic Carbon Nanotubes

by H. Kataura & Y. Miyata SPIE Newsroom, accessed 26 Sep 2006 A carbon nanotube (CNT) can exhibit either metal or semiconductor electronic behavior, depending on the molecule's chirality. The metallic variety is used in conductive films and transparent electrodes, while the semiconducting type is in great demand for high-performance field effect transistors (FETs). Unfortunately, current synthesis methods can't produce pure batches of either type, probably because of structural similarities, and instead generally produce twice as many semiconducting nanotubes as metallic nanotubes. This mixture can degrade application performances. For example, metallic CNTs reduce an FET's on/off current ratio, while semiconducting CNTs lower a thin film's overall conductivity. Thus, it is essential to have an effective way to separate the two types in order to better realize CNT potential. Read more