Metal-insulator-semiconductor electrostatics of carbon nanotubes

Carbon nanotube metal-insulator-semiconductor capacitors are examined theoretically. For the densely packed array of nanotubes on a planar insulator, the capacitance per tube is reduced due to the screening of the charge on the gate plane by the neighboring nanotubes. In contrast to the silicon metal-oxide-semiconductor capacitors, the calculated C-V curves reflect the local peaks of the one-dimensional density-of-states in the nanotube. This effect provides the possibility to use C-V measurements to diagnose the electronic structures of nanotubes. Results of the electrostatic calculations can also be applied to estimate the upper-limit on-current of carbon nanotube field-effect transistors. (C) 2002 American Institute of Physics.