Contactless Probing of the Intrinsic Carrier Transport in Single-Walled Carbon Nanotubes

TL;DR

This study introduces a contactless dielectric force microscopy method to probe intrinsic carrier transport in single-walled carbon nanotubes, correlating it with traditional FET measurements and revealing local transport barriers.

Contribution

It demonstrates a novel contactless approach to analyze carrier transport in nanotubes, linking dielectric responses with electronic properties and detecting local transport barriers.

Findings

Dielectric responses strongly correlate with FET transport properties.

DC bias voltage in DFM acts like gate voltage in FET.

Local transport barriers are detected at nanometer scale.

Abstract

Intrinsic carrier transport properties of single-walled carbon nanotubes are probed by two parallel methods on the same individual tubes: the contactless dielectric force microscopy (DFM) technique and the conventional field-effect transistor (FET) method. The dielectric responses of SWNTs are strongly correlated with electronic transport of the corresponding FETs. The DC bias voltage in DFM plays a role analogous to the gate voltage in FET. A microscopic model based on the general continuity equation and numerical simulation is built to reveal the link between intrinsic properties such as carrier concentration and mobility and the macroscopic observable, i.e. dielectric responses, in DFM experiments. Local transport barriers in nanotubes, which influence the device transport behaviors, are also detected with nanometer scale resolution.