Effective Way To Enhance the Electrode Performance of Multiwall Carbon Nanotube and Poly(3,4-ethylenedioxythiophene): Poly(styrene sulfonate) Composite Using HCl-Methanol Treatment

Abstract

In this study, the electrode performance of composite films composed of highly conductive multiwalled carbon nanotubes (MWCNTs) and poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT:PSS) are improved with the use of HCl-methanol (HCl-met) treatment. The HCl-met treatment affects film properties, including surface morphology, optical transmittance, work function (Phi), and electrical conductivity, which are investigated using various kinds of MWCNT/PEDOT:PSS composite systems. As a result of the HCl-met treatment, all MWCNT/PEDOT:PSS films undergo considerable changes in molecular ratio and arrangement between PEDOT and PSS, but their MWCNTs have no chemical/structural transitions. This in turn enhances the electrical conductivity and catalytic activity of the MWCNT/PEDOT:PSS films without changing their other properties. Furthermore, because of these effects, the HCl-met treatment brings about noticeable enhancements in performance as the source/drain electrode in an organic thin-film transistor and as the catalytic counter electrode in a dye-sensitized solar cell.