Mechanism of surface treatments on carbon nanotube transparent conductive films by three different reagents

Transparent conductive films (TCFs) were fabricated via a spray-coating method with a solution prepared by dispersing single-walled carbon nanotubes (SWCNTs) in deionized water with sodium dodecylbenzene sulfonate (SDBS) as surfactant. We explored the mechanism of HNO₃ treatment by treating TCFs with different reagents. After being treated with different concentrations of reagents by HNO₃, HCl, and NaNO₃ to lower the sheet resistance of TCFs, the properties of TCFs were further characterized by a UV-VIS spectrophotometer, a four-point probe method, atom force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. In this study, we conclude that the HNO₃ treatment results in a decrease in the sheet resistance of the TCFs due to the combined effect of acidity and oxidizability. The strong interaction of the strong acidity and strong oxidizing property of HNO₃ causes the SDBS to be removed. To further improve the film conductivity of the TCFs, the experimental conditions of the HNO₃ treatment were optimized.