Page 138 - Academic Press Encyclopedia of Physical Science and Technology 3rd Polymer

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Encyclopedia of Physical Science and Technology En012j-597 July 26, 2001 11:8

Polymers, Electronic Properties

J. Mort
Xerox Corporation

I. Conductivity
II. Electronic States
III. Triboelectricity and Electrets
IV. Piezo- and Pyroelectricity
V. Photoelectronic Properties of Pendant-Group
Polymers
VI. Conducting Polymers: Polyacetylene
VII. σ-Bonded Polymers
VIII. Applications

GLOSSARY originating from the condensed nature of a solid, for
electronic carriers.
Amorphous Pertaining to a structurally disordered mate- Fermi level Parameter in quantum statistics defining the
rial in which the building blocks, atoms, or molecules energy of the highest occupied energy states.
are randomly arranged without the periodicity charac- Geminate recombination Recombination of photogen-
teristic of a crystalline solid. erated electron–hole pairs before they ever become free
Carrier range Distance an excess electronic carrier can of their mutual Coulomb attractive field.
move in an applied field E before being immobilized Mobility µ Critical parameter of electronic charge trans-
by trapping. port defined as the carrier velocity per unit field.
Chromophore Strictly speaking, a term denoting the Molecular ion Charged molecular unit with either an ex-
molecular unit responsible for the color of a cess (anion) or deficit (cation) of electronic charge.
molecular solid but also used as a generic de- Pendant group Molecular unit attached to the polymer
scription of a molecular unit such as a pendant backbone at an angle to the chain direction.
group. Piezoelectricity Change in electric polarization due to
Conjugated polymer Polymer consisting of alternating either stress or strain.
single and double bonds. Plasmon Collective excitation of free or bound carriers.
Electret Material in which real or polarization charges Poling Technique for forming electrets involving the ap-
can be stored for a long period of time. plication of a high electric field at an elevated tempera-
Extended states Used synonymously with the term band ture followed by cooling to room temperature with the
states and describing a range of allowed energies, field still applied.

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