Transport and TEM on individual nanotubes and nanotube peapods

For the first time, transport measurements in field-effect transistor configuration and TEM investigations on the same individual single-walled carbon nanotubes (SWNTs) have been performed. So far approaches for combining transport and TEM on the same nanotube only allowed for measuring the output characteristics I_sd(V_sd), i.e., the dependence of the current I_sd through the tube on the bias voltage V_sd. Applying our new method of underetching a Si/SiO₂ substrate from the edge of a chip after the transport measurements, we can additionally get the transfer characteristics I_sd(V_g), i.e., the gate response of the current, which provides crucial information about the electronic properties of the system investigated. After the transport measurements and the etching process the samples can be viewed in the TEM, which enables us to check, whether a contacted nanotube is really a single tube or a thin bundle and whether a tube is filled with fullerenes ("peapod").