Controlled transformations in transparent conducting films fabricated from highly stable hydrophilic dispersions of SWNTs through surface charge manipulation and acid treatment conditions

Single wall carbon nanotubes (SWNTs) are considered to be one of the potential candidates for the production of transparent conducting films (TCFs), which can be used in many applications, e.g., touch panels, displays, and polymer solar cells. However, for making optimum usage of the superior properties of SWNTs, a better understanding on the processing and fabrication of thin films is essential. In this work, the effects of the purification conditions of SWNTs, the stability of their dispersions as a function of pH, and the performance of TCFs fabricated from dispersions of different pH are studied. The figure of merit sigma(dc)/sigma(oc) for such films can be increased by factor of 2 when the pH of the SWNT dispersion is increased, i.e., the optical and electrical performance is improved significantly. We also report the surface charge-manipulated transformations in transparent conducting films fabricated from SWNT dispersions of different pH values. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim