Section X. Organic materials
Comparison of conductivity produced in polymers and carbon films by pyrolysis and high energy ion irradiation

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Abstract

We compare the effects of pyrolysis and 2 MeV Ar+ ion irradiation in modifying the conductivity of polymeric and carbon films. Chemical degradation (in the polymer films) and structural rearrangement (in both polymer and carbon films) are introduced by either process. Metallic carrier densities (1022 − 1023cm−3) have been observed in these films by Hall measurements. Transmission electron microscope (TEM) images show the formation of graphitic ordering with correlation lengths ∼ 20 Å in the highly conductive films, with planes oriented parallel to the film surface. Crystalline graphite has a small overlap of the conduction and valence bands (≲ 30 meV), and consequently a low carrier density (∼ 1018 cm−3). We believe the modified carbon films to have larger overlap of the bands (∼1 eV) at the Fermi level, due to significant smearing of the carrier energy associated with the short scattering (correlation) lengths. While pyrolysis and ion irradiation produce similar end results, ion irradiation can yield ultimately higher carrier densities in these films as the ion-annealing process is self-limiting in terms of the extent of crystalline order produced in the film.

References (13)

  • E.K. Sichel et al.

    Solid St. Commun.

    (1982)
  • J.H. Mooij

    Phys. Stat. Sol.

    (1973)
  • U. Sander et al.

    J. Phys. Colloq.

    (1979)
  • B.S. Elman et al.

    Phys. Rev.

    (1981)
  • T. Venkatesan et al.

    J. Appl. Phys.

    (1983)
There are more references available in the full text version of this article.

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