Microstructure-dependent electrochemical properties of chemical-vapor deposited poly(3,4-ethylenedioxythiophene) (PEDOT) films

[Display omitted] •Control over nanocrystallite orientation relative to surface plane achieved via CVD.•Microstructure impacts redox properties and electrochemical conditioning.•Power density scales with maximum peak current and ion transport.•Energy density tracks with crystallinity and electrical conductivity. Conductive polymer electrodes hold exceptional promise in energy conversion technologies and bioelectronics due to the inherent mechanical flexibility and synthetic tunability of physical, chemical, and electronic properties. Solution-processing is favorable to retain low-cost but can often result in heterogeneity of physical and electronic structure due to non-conjugated side chains and polyionic dopants creating insulating domains. Such a complex landscape limits control and systematic understanding of fundamental properties including electrical and ionic transport and rates of electron transfer central to overall device efficiencies. Oxidative chemical vapor deposition (oCVD) offers a promising route to simultaneously synthesize and deposit conductive polymer films at low temperatures (