Characterization of highly conducting, ultra-thin polyaniline films produced by evaporative deposition

The chemical and electronic properties of ultra-thin polyaniline films produced by the evaporative deposition of emeraldine was studied using high resolution electron energy loss spectroscopy (HREELS). Vapor-deposited polyaniline films were found to consist of relatively short chains and exist in an oxidation state close to that of the starting emeraldine powder. Films doped with HCl exhibited a plasma frequency in the far-IR at low temperature. This indicates that ultra-thin, vapor-deposited emeraldine films are highly crystalline and, when doped with HCl, exhibit conductivities several orders of magnitude higher than those of HCl-doped emeraldine films produced by wet-chemical deposition techniques. The results of this study suggest that evaporative deposition may be an attractive fabrication technique for the production of polyaniline thin films for future applications in microelectronics.