Electrical, structural and optical properties of amorphous carbon

https://doi.org/10.1016/0022-3093(77)90035-7Get rights and content

Abstract

The planar and transverse electrical resistivity of amorphous carbon (a-C) films getter-sputtered at low temperature (77–95 K) is well-fitted by the expression ϱ = ϱ0exp(T0/T)14 The exponent T0 being approximately the same in both cases (≈ 7 × 107 K) suggests that the amorphous films are isotropic. Films thinner than 600 Å display a two-dimensional hopping conductivity from which one deduces a density of states N(EF) at the Fermi level of 1018 eV−1 cm−3 and a radius of the localized wave functions (a) of 12 Å. Tunneling experiments and optical absorption measurements are consistent with a pseudogap of approximately 0.8 eV. Electron diffraction experiments indicate that a-C films consist of a mixture of diamond and graphite bonds; this fact taken in the light of the other experiments would suggest that the graphite bonds act as the localized conduction states.

References (28)

  • M. Morgan

    Thin Solid Films

    (1971)
  • J.J. Hauser

    Solid State Commun.

    (1975)
  • J.J. Hauser et al.

    Solid State Commun.

    (1976)
  • M.L. Knotek

    Solid State Commun.

    (1975)
  • J.J. Hauser

    Solid State Commun.

    (1973)
  • R.S. Bauer et al.

    Solid State Commun.

    (1972)
  • C.J. Adkins et al.

    Phil. Mag.

    (1970)
  • C.J. Adkins et al.
  • M.D. Blue et al.

    J. Appl. Phys.

    (1957)
  • R. Grigorovici
  • T.M. Donovan et al.

    Phys. Rev. Letters

    (1971)
  • J.J. Hauser et al.

    Phys. Rev.

    (1973)
  • J.J. Hauser

    Phys. Rev.

    (1973)
  • Cited by (178)

    • Diamond-like carbon coatings for cryogenic operation of particle detectors

      2023, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
    • Microstructure design of C/C composites through electrochemical corrosion for brazing to Nb

      2022, Journal of Materials Science and Technology
      Citation Excerpt :

      Higher extent of graphitization induced the lower resistance. The resistivity of carbon fiber and amorphous graphene was about 7 × 10−3 and 0.1 Ω m, respectively [23,24]. It will induce the different corrosion rate between fiber and matrix.

    • The effect of vacuum annealing on the structure and properties of the electrically conductive a-CN coating

      2021, Vacuum
      Citation Excerpt :

      A similar behavior was observed for ta-CN films in Ref. [9]. Electrical conductivity in amorphous materials usually occurs by jumping an electron between localized states distributed in the mobility gap, either near the edge of the conduction band, near the Fermi level, or by conduction of electrons in extended states of the conduction band [16,17]. Typically, VRH conductivity occurs when the internal microscopic disorder is so high that tunneling between the nearest nodes becomes unlikely.

    • Light-weight and highly flexible TaC modified PyC fiber fabrics derived from cotton fiber textile with excellent electromagnetic shielding effectiveness

      2020, Chemical Engineering Journal
      Citation Excerpt :

      From the XRD and XPS results, we indicate these particles as the TaC phase. Due to the better electrical conductivity of TaC than that of PyC [19,48], the TaC particles appear in a brighter contrast than the PyC substrate in SEM images. With the increase of the suspension concentration, the content of TaC in the derived sample (S-3) increased gradually.

    View all citing articles on Scopus
    View full text