Highly Uniform and Conducting Single-Walled Carbon Nanotube Thin Films via Controlling the Dewetting Phenomenon.

Abstract

Carbon nanotubes (CNTs) have received substantial attention as alternatives to indium tin oxide for the production of transparent conductors. However, problems associated with the dewetting of liquid thin films have hindered the reliable fabrication of networked conducting CNT films via solution-based processes. In this study, the dewetting of liquid thin films containing single-walled carbon nanotubes (SWCNTs) on substrates is successfully retarded by simply adding ethylene glycol to the SWCNT dispersion, and highly uniform SWCNT thin films are obtained using the meniscus-dragging deposition (MDD) method. The dewetting-free coating conditions for the uniform SWCNT films are determined by calculating the dewetting and drying times of the liquid thin films formed by the MDD method. When the dewetting time was 2.5 times longer than the drying time of the liquid thin layers, uniform SWCNT films are formed over the entire substrates without breakage or rupture of the films. In addition, the transmittance and sheet resistance of the transparent SWCNT films are easily controlled over a wide range by varying the coating parameters.