Rapid annealing and cooling induced surface cleaning of semiconducting carbon nanotubes for high-performance thin-film transistors

Abstract

Semiconducting single-walled carbon nanotube (s-SWCNT) films require high-quality preparation and optimization for use in carbon-based electronic devices. Tremendous progress has been made in s-SWCNTs sorting technology with conjugated polymers to obtain high-purity s-SWCNT films. However, one drawback of this technology is residual polymer wrapping on s-SWCNT surfaces. These residual polymers have poor conductivity, impeding the charge transport between the nanotube-electrode and the nanotube-nanotube. To address this issue, a rapid annealing and cooling method was developed for cleaning the s-SWCNT films, which can thoroughly remove the wrapped polymers from the surfaces of s-SWCNTs, effectively reducing the contact resistance between the nanotube-metal electrode and the nanotube-nanotube. Our results show that thin-film transistors made of cleaned s-SWCNTs exhibited improved performance when compared with pristine s-SWCNT films rinsed with an organic solvent. The contact resistance between the s-SWCNTs and the electrode was reduced by 700%, while the on–state current density of the CNT-TFTs increased by nearly 600%. These results thus demonstrated the effectiveness of our developed method for removing polymers from the surfaces of s-SWCNTs, which is essential for the further development of carbon nanotube electronic devices and circuits.