Amorphous Semiconductor Switching in Melanins

  title={Amorphous Semiconductor Switching in Melanins},
  author={John E. McGinness and Peter Corry and Peter H. Proctor},
  pages={853 - 855}
Melanins produced synthetically and isolated from biological systems act as an amorphous semiconductor threshold switch. Switching occurs reversibly at potential gradients two to three orders of magnitude lower than reported for inorganic thin films, and comparable to gradients existing in some biological systems. Of a number of other biological materials tested, only cytochrome c acted similarly, but at the high potential gradients reported for thin film amorphous semiconductors. 

Semiconductor properties of melanins prepared from catecholamines.

The melanins examined show significant differences in conductivity, thermal activation energy and photocurrent intensity values, which reflect the structure differences of catecholamine-melanin polymers.

Device-quality electrically conducting melanin thin films

Thin films based on melanin are prepared and characterized. The films display electrical conductivities comparable with amorphous silicon as well as a host of other interesting and potentially useful

The Study of Ordered Melanin Films

Two types of melanin films: self-arranged ordered films and amorphous films have been studied in the present paper. The structure, absorption spectra, spectra of photovoltage, and spectra of

Charge Transport in Melanin, a Disordered Bio-Organic Conductor

Melanins are biological macromolecules with many roles in the biosphere including as pigments and photoprotects. They have been shown to possess several interesting physical and chemical properties.

Studies of Melanin Pigments of Different Origin

ABSTRACT Absorption spectra and spectra of time-resolved and stationary photoluminescence (PL) measured at low and room temperatures have been investigated for the water-soluble and water-insoluble

Role of semiconductivity and ion transport in the electrical conduction of melanin

It is shown that hydration of melanin shifts the comproportionation equilibrium so as to dope electrons and protons into the system and explains why melanin at neutral pH only conducts when “wet” and suggests that both carriers play a role in the conductivity.



Mobility Gaps: A Mechanism for Band Gaps in Melanins

The semiconductor behavior of melanins is reviewed and compared with quantum mechanical models of conduction in amorphous solids, and an investigation of the specific conduction mechanisms operative in melanins in terms of theAmorphous model should reveal important aspects of the band structure.

Preswitching and postswitching phenomena in amorphous semiconducting films

Low‐duty‐cycle pulsed dc switching experiments have been performed on a variety of thin‐film Te‐based semiconducting glasses. No premonitory effects are observed in the current‐time profile of the

Electron-transfer factors in psychosis and dyskinesia.

  • P. Proctor
  • Psychology, Medicine
    Physiological chemistry and physics
  • 1972
SUMMARY In man, chronic elevated systemic levels of compounds possessing electron-transfer properties are typically associated with one or more of a triad of characteristic. signs. These are

Critical Review of Solid State Sciences (Chemical Rubber

  • 1971

We thank M. Romsdahl and S. Moss for their assistance in this work

  • AEC contract AT