Electrical transport properties of small diameter single-walled carbon nanotubes aligned on ST-cut quartz substrates

TL;DR

This study introduces a method to measure electrical transport in individual aligned single-walled carbon nanotubes on quartz, revealing substrate interactions and low-temperature quantum behaviors relevant for device development.

Contribution

It provides a novel approach for isolating and characterizing electrical properties of single SWNTs on quartz, including detailed analysis of substrate effects and quantum phenomena at low temperatures.

Findings

Significant substrate interaction indicated by G-band up-shift in Raman spectra.

Observation of Tomonaga-Luttinger liquid and Coulomb blockade behaviors.

Transition from semiconducting to insulating state at low temperatures for smaller diameter SWNTs.

Abstract

A method is introduced to isolate and measure the electrical transport properties of individual single-walled carbon nanotubes (SWNTs) aligned on an ST-cut quartz, from room temperature down to 2 K. The diameter and chirality of the measured SWNTs are accurately defined from Raman spectroscopy and atomic force microscopy (AFM). A significant up-shift in the G-band of the resonance Raman spectra of the SWNTs is observed, which increases with increasing SWNTs diameter, and indicates a strong interaction with the quartz substrate. A semiconducting SWNT, with diameter 0.84 nm, shows Tomonaga-Luttinger liquid and Coulomb blockade behaviors at low temperatures. Another semiconducting SWNT, with a thinner diameter of 0.68 nm, exhibits a transition from the semiconducting state to an insulating state at low temperatures. These results elucidate some of the electrical properties of SWNTs in this unique configuration and help pave the way towards prospective device applications.