Optimizing processes of dispersant concentration and post-treatments for fabricating single-walled carbon nanotube transparent conducting films

This study evaluated the effect of sodium dodecyl benzene sulfonate (SDBS) as dispersant for the dispersion of purified single-walled carbon nanotubes (SWCNTs) in water in terms of dispersibility dependence on electrical conductivity of SWCNT transparent conducting film (TCF) performance. SWCNT TCFs were prepared by different proportions of CNTs/SDBS solution to find out the optimum SDBS concentration according to the film resistance of pristine and after post-treatment by nitric acid. TCFs fabricated with the aqueous solution by the ratio of CNTs/SDBS 1:5 gave the lowest sheet resistance and the highest transmittance. The TCFs were then further treated with thionyl chloride to improve their conductivity. Low sheet resistance (86 Ω/□, 80%T) was achieved. The dispersion condition of CNTs/SDBS aqueous solution was characterized by field-emission scanning electron microscopy, while the X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the dispersion and doping mechanism treated with nitric acid and thionyl chloride.