Chiral-Index Resolved Length Mapping of Carbon Nanotubes in Solution Using Electric-Field Induced Differential Absorption Spectroscopy

TL;DR

This paper introduces a simple, in-situ electric-field spectroscopy method to measure the length distribution of single-walled carbon nanotubes with chiral index resolution, verified by atomic force microscopy.

Contribution

The authors develop and calibrate a novel EFIDAS technique for chiral-index-resolved length measurement of SWCNTs in dispersion, enabling in-situ and low-cost analysis.

Findings

Method accurately measures SWCNT length in dispersion.

Chiral index influences length distribution, detectable by the method.

Calibration with atomic force microscopy confirms reliability.

Abstract

The length of single-walled carbon nanotubes (SWCNTs) is an important metric for the integration of SWCNTs into devices and for the performance of SWCNT-based electronic or optoelectronic applications. In this work we propose a rather simple method based on electric-field induced differential absorption spectroscopy (EFIDAS) to measure the chiral-index-resolved average length of SWCNTs in dispersions. The method takes advantage of the electric-field induced length-dependent dipole moment of nanotubes and has been verified and calibrated by atomic force microscopy. This method not only provides a low cost, in-situ approach for length measurements of SWCNTs in dispersion, but due to the sensitivity of the method to the SWCNT chiral index, the chiral index dependent average length of fractions obtained by chromatographic sorting can also be derived. Also, the determination of the chiral-index resolved length distribution seems to be possible using this method.