Optical Characterizations and Electronic Devices of Nearly Pure (10,5) Single-Walled Carbon Nanotubes

TL;DR

This study demonstrates the first successful fabrication of single-chirality (10,5) SWNT FETs with 99% purity using a novel ion exchange chromatography method, significantly advancing the development of high-performance nanotube-based electronic devices.

Contribution

It introduces a new DNA sequence for efficient separation of (10,5) SWNTs and confirms their high purity and device performance, enabling single-chirality nanotube electronics.

Findings

Achieved 99% purity of (10,5) SWNTs

Fabricated FETs with Ion/Ioff ratio up to 10^6

First demonstration of single-chirality SWNT FETs

Abstract

It remains an elusive goal to achieve high performance single-walled carbon nanotube (SWNTs) field effect transistors (FETs) comprised of only single chirality SWNTs. Many separation mechanisms have been devised and various degrees of separation demonstrated, yet it is still difficult to reach the goal of total fractionation of a given nanotube mixture into its single chirality components. Chromatography has been reported to separate small SWNTs (diameter less than 0.9nm) according to their diameter, chirality and length. The separation efficiency decreased with increasing tube diameter by using ssDNA sequence d(GT)n (n=10-45). Here we report our result on the separation of single chirality (10,5) SWNTs (diameter = 1.03nm) from HiPco tubes with ion exchange chromatography. The separation efficiency was improved by using a new DNA sequence (TTTA)3T which can recognize SWNTs with the specific chirality (10,5). The chirality of the separated tubes was examined by optical absorption, Raman, photoluminescence excitation/emission and electrical transport measurement. All spectroscopic methods gave single peak of (10,5) tubes. The purity was 99% according to the electrical measurement. The FETs comprised of separated SWNTs in parallel gave Ion/Ioff ratio up to 106 owning to the single chirality enriched (10,5) tubes. This is the first time that SWNT FETs with single chirality SWNTs were achieved. The chromatography method has the potential to separate even larger diameter semiconducting SWNTs from other starting material for further improving the performance of the SWNT FETs.