Electrical transport measurements of nanotubes with known ( n , m ) indices

Because subtle changes in physical structure (chirality) can cause the electronic structure of carbon nanotubes to vary from metallic to semiconducting, the goal of fully controlled nanotube device fabrication has proved elusive. Using a mechanical transfer technique in parallel with optical characterization, we have achieved the goal of placing ‘the nanotube we want, where we want it’. Long nanotubes are grown by CVD across a slit etched through a Si wafer and then examined by Rayleigh scattering. By combining this technique with structural characterization by electron diffraction, we are able to map each spectrum to a unique ( n , m ) structure. After structural characterization, a chosen nanotube can be transferred to a substrate in the desired location, and devices fabricated using standard e‐beam lithography techniques. We have fabricated a number of devices in this manner and are beginning to fully explore the detailed relationship between structure and transport. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)