Carbon Nanotube Transistor Operation at 2.6 GHz

Abstract

We present the first demonstration of single-walled carbon nanotube transistor operation at microwave frequencies. To measure the sourcedrain ac current and voltage at microwave frequencies, we construct a resonant LC impedance-matching circuit at 2.6 GHz. Both semiconducting and metallic nanotubes are measured. Varying the back-gate voltage for a semiconducting nanotube at dc varies the 2.6-GHz source-drain impedance. In contrast, varying the back-gate voltage on a metallic nanotube at dc has no effect on the microwave source-drain impedance. We find the ac source-drain impedance to be different than the dc source-drain resistance, which may be due to the distributed nature of the capacitive and inductive impedance of the contacts to the nanotube. The dynamical (ac) electrical properties of carbon nanotubes are technologically relevant for both active and passive devices made from carbon nanotubes. At dc, it is known that electrons can move without scattering over many micrometers inside a carbon nanotube. 1 We recently analyzed, from a theoretical point of view, the microwave passive 2,3 and active 4,5 electrical properties of nanotubes in some detail. The successful operation of a multiwalled carbon nanotube rf single-electron transistor was recently reported. 6 In this paper, we present the first measurements of the electrical properties of single-walled nanotubes at gigahertz frequencies. 7 In so doing, we demonstrate, for the first time,