Single Carbon Nanotube Transistor at GHz Frequency

TL;DR

This paper demonstrates microwave operation of single carbon nanotube transistors, achieving high transit frequencies up to 50 GHz, revealing their potential for high-speed nanoelectronic applications.

Contribution

It provides the first microwave characterization of top-gated single carbon nanotube transistors, measuring their transconductance and capacitance in the GHz range.

Findings

Transconductance of about 20 microSiemens is consistent across frequencies.

Capacitance per unit length is 60 aF/μm, typical for top-gated devices.

Transit frequency reaches 50 GHz without saturation.

Abstract

We report on microwave operation of top-gated single carbon nanotube transistors. From transmission measurements in the 0.1-1.6 GHz range, we deduce device transconductance gm and gate-nanotube capacitance Cg of micro- and nanometric devices. A large and frequency-independent gm of about 20 microSiemens is observed on short devices, which meets the best dc results. The capacitance per unit gate length of 60 aF/micrometer is typical of top gates on a conventional oxide with a dielectric constant equal to 10. This value is a factor of 3-5 below the nanotube quantum capacitance which, according to recent simulations, favors high transit frequencies . For our smallest devices, we find a large transit frequency equal to 50 GHz with no evidence of saturation in length dependence.