High-mobility semiconducting nanotubes

Carbon nanotube transistors with channel length exceeding 300 microns have been fabricated. The gate-voltage dependence of carrier transport through these long-channel transistors is similar to short channel (few micrometer) transistors. We place a conservative lower bound for the hole mobility in nanotube transistors at 20,000 cm(2)/V(.)s at room temperature, and offer evidence that the mobility is much greater. This high mobility corresponds with a mean free path for holes of 2.9 mum at a gate voltage of -10 V.