Effect of carbon nanotube types in fabricating flexible transparent conducting films

Flexible transparent conducting films (TCFs) were fabricated using different types of carbon nanotubes (CNTs). Single-walled CNTs (SWCNTs), double-walled CNTs, thin multi-walled CNTs, and multi-walled CNTs were used to investigate the material effect on the optimal film performance of flexible TCFs. The CNTs were dispersed in deionized water with sodium dodecyl sulfate (SDS) and compared with CNTs dispersed in dichloroethane. These CNT solutions were sprayed onto poly(ethylene terephthalate) substrates by using a spray coater to form CNT films. The quality of the CNTs, the degree of dispersion, the film's morphology, and the performance of the TCFs were characterized and analyzed. We found that the SWCNTs were the best candidate to give the lowest sheet resistance and the highest transmittance among these types of CNTs. The SWCNT film's conductivity was further enhanced by a factor of four with a negligible change in the transmittance in the visible range by using a nitric-acid treatment.