Organic Semiconductor Homepage

Organic semiconductor research is important not only in electronics, but because many biological materials are semiconductors. Further, organic semiconductors such as melanin figure in human diseases. Thus, this field spans disciplines from the most advanced quantum physics to the causes and treatment of disease.

A Little Revisionist History

In 1963, Australians BA Bolto, R McNeill and DE Weiss reported passive high conductivity in iodine-"doped" oxidized polypyrrole. A copy of their paper is posted Here. They achieved a conductivity of 1S/cm. These authors also described the effects of iodine doping on conductivity, the conductivity type (n or p), and electron spin resonance studies on polypyrrole. Likewise, these authors noted an Australia patent application (5246/61, June 5, 1961) for conducting polypyrrole. After an exausting search, this appears to be the first report of high conductivity in the linear-backbone polyacetylene-black or "melanin" class of polymers. Unfortunately, this paper was too early and was "lost" for decades. Its priority should now be recognized, at least until something even earlier comes along.

Similarly, the first organic semiconductor active device involved the polyacetylene-derivative melanin. This this case, this was a mixed copolymer of polyacetylene, polypyrrole, and polyaniline. This was a bistable switch with a highly-conductive "ON" state. Melanin was also the first conductive polymer to be used in an energy storage device( "battery" ) application. Likely, this will generate some controversy over the 2000 Nobel award in chemistry, which was given for a similar discovery made three years later with another polyacetylene derivative. But see here for an second opinion.

Here are some links.

IEEE review: The Dawn of Organic Electronics

2000 Nobel Prize in chemistry -- allegedly for the (second) discovery of high conductivity polyacetylene derivatives. Or perhaps the third, counting the "ON" state of the McGinness device.

"On" state of Melanin conductivity of less than 100 ohm-cm

The Function of Melanin

Why electronic processes are important in disease

Conjugated polymers as photovoltaics

Opticoelectronic Properties of Disordered Organic Semiconductors ( Thesis )

Many Organic Semiconductors are Natural Products

CalPoly Polymer Electronics Lab ( many good links_)

At the moment this page is still under construction, but will eventually contain many additional links to this fascinating area.

Peter H. Proctor, PhD, MD

Our Credentials: I have graduate degrees in Pharmacology and Biophysics, as well as being a practicing physician. My collaborator, John McGinness, is a physician who also has a PhD in solid state physics from Rice University. Our specific area of research is active electronic mechanisms in disease--- stuff like free radicals, etc.


."The most simple melanin can be considered the acetylene-black from which it is possible to derive all the others..... Substitution does not qualitatively influence the physical properties like conductivity, colour, EPR, which remain unaltered." from The Nature of Animal Blacks

R. Nicolaus, pioneer in melanin chemistry ( "acetylene-black" = polyacetylene)







Keywords: organic semiconductors hopping nobel prize melanin localized states soliton polyaniline polyacetylene amorphous density of states polythiophene chemistry 2000 mobility gap semiconductor black materials dihydroxyindole dhi organic phonon charge-transfer doped doping electron donor acceptor complex biological substantia nigra parkinsonism psychosis dyskinesia deafness quantum band hole metal copper controversy questionable wilson's disease iron transition series metal hemochromatosis locus caeruleus iodine iodism pigment cell nitric oxide nitrone tempo tempol peroxinitrite biological manganese liver inner ear pars compacta midbrain electrochemical free radical esr spin resonance spin traps label interfaces crystaline polymer superoxide dismutase threshold switch battery energy storage device

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Electrical, optical and magnetic behavior
Insulating films
Insulating surfaces
Metal/semiconductor interfaces
Schottky barrier
Other interfaces
Metal-semiconductor non-magnetic heterostructures
Semiconductor-semiconductor heterostructures
Superconductor-semiconductor heterostructures
Heterostructures with non-linear optical response