Fabrication of a large-area, flexible and color-neutral single-wall carbon nanotube:sodium dodecylbenzene sulfonate/poly-(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) transparent conductive film having a new conduction mechanism

Abstract Flexible transparent conductive films (TCFs) are vital to promote the development of flexible and foldable devices including touch panels, displays, organic solar cells, etc. We have prepared a large-area, flexible, and color-neutral single-wall carbon nanotube:sodium dodecylbenzene sulfonate/poly-(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (SWCNT:SDBS/PEDOT:PSS) composite TCF on a poly(ethylene terephthalate) substrate by a spray coating method. The TCF has a sheet resistance of 178 Ω sq −1 with 85% transmittance at 550 nm. The light transmission characteristics of the films can be tuned by changing the mass fraction of SWCNTs. When the mass fraction of SWCNTs is higher than 4 wt.%, the original blue tint of the TCFs has disappeared. More importantly, we find that SDBS may play a more important role than the SWCNT network in improving the electrical conductivity of the films by acting as a secondary dopant of PEDOT:PSS, which is different from the traditional understanding and existing explanation about the conduction mechanism of PEDOT:PSS-based composite films.