In situ conductivity of some selected polypyrroles (polypyrrole and po
ly (N-methylpyrrole)) and polythiophenes (poly(4,4'-dipentoxydithiophe
ne), poly(dithienylethylene) and two crown-5-substituted poly(cyclopen
tadithiophenes)) as a function of oxidative doping level is reported.
The relationship is in general composed of three segments (threshold,
Linear increase and plateau). Doping-charge thresholds of conductivity
are explained on the basis of charge pinning of polarons and bipolaro
ns by anions and (in polythiophenes) by pi-dimerization of polarons. (
C) 1998 Elsevier Science S.A. All rights reserved.