Conducting films comprising conducting polymers and carbon nanomaterials have
gained a lot of interest for applications in several fields, including transparent electrodes, supercapacitors, light-emitting diodes (LEDs), polymer solar cells (PSCs), etc. One of the main motivations
is the replacement of costly oxides and degradable materials, like indium tin oxide (ITO). On the
other hand, graphene oxide (GO) has emerged as an ideal filler to reinforce polymeric matrices owing to its large specific surface area, transparency, flexibility, and very high mechanical strength.
Nonetheless, functionalization is required to improve its solubility in common solvents and expand
its practical uses. In this work, the potential of polymer nanocomposites based on hexamethylene
diisocyanate (HDI)-functionalized GO (HDI-GO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) for use as active layers (ALs) or interfacial layers (IFLs) in PSCs has been assessed. Conventional deposition techniques applied to thin films were tested for the developed
nanocomposites. Deposition methods included drop and spin casting, where different type of substrates, as clean glass and glass/ITO were tested. The results of deposition essays were analyzed by
atomic force microscopy (AFM) and UV-Vis spectroscopy. In addition, thermal evaporation was
tried with the aim of obtaining homogeneous layers. The layers obtained by drop casting showed
poor film quality, with large aggregates. On the other hand, spin coating lead to layers not fully
wetting the substrate. New synthesis procedures for the nanocomposites and/or alternative treatments of the substrate surface will be investigated in the future to optimize their composition and
properties (i.e., transparency) and improve their suitability for use in PSCs.