Polymer-assisted dispersion of single-wall carbon nanotubes for transparent conducting film fabrication

Transparent electrodes, for instance ITO (indium tin oxide), are used in electronic devices such as touch screen, flat panel display, and solar cell technologies. It is costly to pattern and has a tendency to crack when used due to its brittle nature. The development of technologies to deliver low cost flexible alternatives using single walled carbon nanotubes (CNTs) are fledgling but has a promising potential in optoelectronic devices, such as touch panel in smart mobile, and transparent conducting films (TCF), etc. Although carbon nanotube (CNTs) electrodes show promise in possessing suitable TCF properties, poor dispersion in common solvents have limited their practical usage. CNTs-based transparent conducting films have been demonstrated in various methods, such as vacuum filtration, transfer printing, drop casting, dip-coating, etc. However, most of the processes only promise uniform performance in small area, which cannot be expanded to practicable scale. On the other hand, the rod and slot coating being developed solve these drawbacks of the aforementioned processes. But in this method, the CNTs need to be functionalized, which increase the cost of production. Here, we propose a method to fabricate CNTs films with high transparency, electrical conductivity, and relatively uniform on large (10 cm×10 cm) substrate by ultrasonic spray coating.