Diameter distribution control of single-walled carbon nanotubes by etching ferritin nanoparticles

Abstract

We focused on controlling the diameter of single-walled carbon nanotubes (SWNTs) by controlling the ferritin catalyst diameter using reactive ion etching (RIE). The average diameter of ferritin decreased by about 26.5% upon RIE treatment, which resulted in the decrease of the mean diameter of the SWNTs by about 34% with a small diameter distribution. This was demonstrated by both atomic force microscopic and Raman spectroscopic measurements. We found that the current on/off ratio of the SWNT thin film transistors was significantly improved after the catalyst treatment. It was estimated that the purity of the semiconducting SWNT also increased from 58.8 to 92.4%.