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Keywords:

  • Conducting polymers;
  • VRH;
  • Polarons;
  • DC conductivity;
  • AC conductivity;
  • Photo conductivity

Abstract

Polydiheteroarylenemethines show a relatively high electrical conductivity. Two-coplanar-electrode measurements give a high surface conductivity of 10−9 S/□ and a high mobility up to 1 cm2 V−1. Depending on the type of side group, doping with iodine served to raise the conductivity by five orders of magnitude. Optical absorption analysed with DC and AC conductivity data revealed two components in the transport process: A VHR (variable range hopping) process shifting to a band tail polaronic process as the degree of polymerisation increases, corresponding to a very characteristic transition in the AC conductivity. The hopping process corresponds to an AC conductivity frequency power law dependence of ω0.66, whereas the polaronic process corresponds to a power law dependence of ω0.1.