(709d) Synthesis of Conducting Copolymers of 3,4-Ethylenedioxythiophene and 3-Substituted Thiophenes by Oxidative Chemical Vapor Deposition

In recent years, polymeric electronic materials are becoming major areas of research interests because of exponentially increasing demand for flexible electronic devices. Some of the major application areas of these polymers are in fabricating OLED, photovoltaic cells, sensors devices. There are various techniques to synthesize and fabricate these materials for device applications, including spin coating and solution processing. However, most of the currently applied methods involve multi-step synthesis and large quantities of solvents for fabrication. In this work, we present a single step and solvent free preparation of thin conducting copolymeric films by oxidative chemical vapor deposition (oCVD) process at low temperature. Here, 3,4-ethylenedioxythiophene (EDOT) and 3-substituted thiophene monomers were employed to synthesize conducting copolymeric films. Iron chloride was used as an oxidant during the vapor phase polymerization step, as well as a dopant in the polymeric system in order to make it conductive. The copolymeric films were characterized by FT-IR, UV-Vis and X-ray photoelectron spectroscopies and 4-point probe measurements. The available functional groups in the copolymers were used for further derivatization reactions. This low temperature oCVD process shows promises for coating any substrate, for example, paper, plastics, silicon and glass with highly conducting, conformal polymeric films.