A facile method to tune electronic properties of carbon nanotube films

Abstract

We report a simple approach of tailoring electronic properties of carbon nanotube (CNT) films. The process was carried out in the gas phase using fuming nitric acid vapors, gases generated from piranha solution or ozone in high and low concentration in O2 as reactants. The results showed a significant alteration in terms of electrical resistance, wherein it was changed by –50% up to +1,300% depending on the employed conditions. Furthermore, as a result of chemical functionalization of the CNT backbone, we witnessed changes to the sample morphology both on the micro- and nanoscale, what could be an asset. Most interestingly, fuming HNO3 treatment introduced carboxylic and phenolic groups to the structure and as a result of hydrogen bonding, we observed bundling up of the material. This strategy could be a tool to yield CNT macroassemblies of predetermined electronic and structural properties without the need of problematic multi-step solution processing.