Poly(triarylamine) composites with carbon nanomaterials for highly transparent and conductive coatings

We report on the fabrication of transparent, conductive, mechanically robust electrode composites of poly(triarylamine) (PTAA) doped with different concentrations of carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs). Additionally, the effects of nanofiller surface modification with amines were characterized by comparing the transparency, conductivity, and mechanical properties to composites with unmodified nanofillers. The optimization of the concentrations and fabrication parameters resulted in films with high transparency, improved electrical conductivity, and superior mechanical properties. Amine-functionalized nanofillers more readily dispersed into the matrix, and the addition of 1 wt% amine-CNTs resulted in a composite film with a conductivity of 1.1 S cm^{− 1} and a transparency of 90–95% in the visible spectrum at a sub-100 nm thickness. At low doping concentrations, composites with amine-functionalized nanofillers exhibited a 100% increase in fracture energy compared to composites with unmodified nanofillers, an effect attributed to increased plasticity of the doped polymer. These findings have applications in many electronic devices that utilize organic semiconducting layers, such as organic light emitting diodes and perovskite photovoltaics.