Fabrication of single walled carbon nanotubes/poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) layers under enhanced gravity drying

• A technique to fabricate conductive films of SWCNT/PEDOT:PSS is presented.
• The technique is based on enhanced gravity drying.
• Improved interpenetration of the bilayer SWCNT/PEDOT:PSS system
• Enhanced gravity increases the p-type conductivity of the film.
• Impedance spectroscopy confirms the improvement on the electrical properties.

In this contribution, we explore the use of enhanced gravity in order to achieve composite films of single walled carbon nanotubes (SWCNTs)/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) with improved properties. The samples were characterized by atomic force microscopy, scanning electron microscopy, and electrochemical impedance spectroscopy, in order to determine the differences caused by the enhanced gravity. Impedance spectroscopy results show that there is an improvement of the electrical properties of the SWCNT/PEDOT:PSS junction, manifested as lower contact resistance, modified chemical capacitance, and induced p-type doping. A force-induced interpenetration of the polymer into the SWCNT network and the efficient removal of water and PSS are proposed to explain the results. The transparency and electrical properties of these films forecast their application as a buffer layer in organic solar cell heterojunctions, or as hole transporting materials in perovskite-based solar cells.