Poly(3,4-ethylenedioxythiophene) (PEDOT) nanofilm was formed on an oxidized Si wafer surface via vapor phase polymerization (VPP) by using FeCl 3 as the oxidant mixed with poly-urethane diol (DUDO) as a base inhibitor and poly(ethylene glycol)-block-poly(propylene glycol)block-poly(ethylene glycol) (PEG-PPG-PEG) as a film forming-mediator.Under optimal VPP deposition conditions (0.11 M of FeCl 3 solution mixed with 8.5 mM of DUDO and 1.38 mM of PEG-PPG-PEG additives dissolved in n-butanol), the deposited nanofilm had outstanding smoothness and density combined with very high electrical conductivity of 6,345 S/cm.A slight increase in the concentration of FeCl 3 to 0.26 M in the oxidant mixture had the effect of forming nanometer-sized holes in the surface of the nanofilm, and their size can be controlled by varying the annealing time at 333 K under vacuum immediately after VPP.This approach enabled a highly conductive PEDOT nanofilm with size-controllable nanoholes to be prepared simply and cost effectively.The method is particularly promising for applications that demand a vastly enlarged surface area and size-induced target-selectivity such as in electrodes for energy storage, flexible transparent conductors, and chemical/biosensors.
Choi et al. (Tue,) studied this question.