Conductive PEDOT Thin Films

About

Conductive films can utilize materials across a wide swath of conventional technologies, with particular use of indium tin oxide (ITO). In addition to favorable conductivity, this material affords the resulting conductive films with other characteristics (e.g., transparency) that make the films amenable to the wide range of applications. ITO is, however, a product of indium, which is a raw material in relatively short supply and, accordingly, continues to increase in price with demand growth for thin, conductive films. Moreover, although favored for certain characteristics, films that utilize ITO can suffer from cracking and brittle failures when subject to bending. This feature some-what limits use of these ITO-based films in combination, e.g., with flexible substrates.  The present technology addresses concerns with ITO-based films to provide candidate materials for use in connection with flexible electronics, and encompasses films and material layers comprising poly(3,4 ethylenedioxytho-pene) (PEDOT). The PEDOT film is made utilizing vapor phase polymerization (VPP) with defined parameters and components. The crystalline structure is favorably organized for films to achieve conductivity in excess of 1000 S/cm, and thus suitable for use as a replacement for ITO-based films.  PEDOT Structure                                        Example of VPP-PEDOT film on PET substrate to                                                                                    illustrate transparency of the film  APPLICATIONS  Consumer Electronics (e.g. phones, televisions, tablet computers, etc.)  Enhancement of solar cells and light-emitting diode (LED) devices  Anti-static coatings  ADVANTAGES  High Conductivity: in excess of 1000 S/cm, well-above most conventional technologies. Conductivity can be tailored based on the application Transmittance: exhibits excellent transmission in excess of 85%  Reliability: outperforms both PEDOT:PSS and ITO in fatigue test of flexure dimension  Transparency: optically transparent and/or exhibits optical properties that transmit light through > 90%  Stretchability: very strechable, conductivity increases upon stretching   I.P.  U.S. Patent Application 14/212,559  RB421