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Chapter 3. Organic Conductor. Conductivity Of Organic Materials. Conductivity s = en m. n: number of carriers; m: mobility of the carriers. Electronic structures of Organic Molecules Core electrons. s electrons, localized between two atoms.
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Conductivity Of Organic Materials
Conductivity s = enm n: number of carriers; m: mobility of the carriers
Electronic structures of Organic Molecules • Core electrons. • s electrons, localized between two atoms. • n electrons, located at a particular heteroatom, usually have high orbital energy and could be promoted easily. • p electrons, delocalized over an array of atoms, usually have high MO energy and could be promoted easily.
Phthalocyanine channel Conductivity is controlled by the phthalocyanine ring. The metal core does not interfere the conductivity. I-
Chain length: Si:12030 Ge: 7440 Sn:10040
(1) Could a charge through delocalize through the p array? (2) Is there any one dimensional conductor in principle? (3) How a charge hop from one p array to another adjacent p array?
Electrical conductivity of polyacetylene Cis-PA s = 1.7 x 10-9 S/cm Trans-PA s = 4.4 x 10-5 S/cm I2 dopeds = 5.5 x 102 S/cm AsF5 dopeds = 1.2 x 103 S/cm Electrochemical Oxidations = 1 x 103 S/cm Li doped s = 2 x 102 S/cm Na doped s = 101-10-2 S/cm
Drawbacks: low solubility. Alkyl side chain for enhancing solubility
When no of phenylene units is larger than 12, the material becomes metallic after doped
Synthesis of Polythiophenes PEDOT.PSS
Polyaniline (PANI) Insulator Conductor
Doping and Undoping PANI doped with H3PO4 was found to be most stable.