The dependence of electronic conductivity upon conjugation length for conducting polymers (original) (raw)

Tuning of Electronic Properties in Conducting Polymers

Collection of Czechoslovak Chemical Communications, 2001

Structural and electronic transitions in poly(thiophenyleneiminophenylene), usually referred to as poly(phenylenesulfidephenyleneamine) (PPSA) upon electrochemical doping with LiClO4 have been investigated. The unusual electrochemical behavior of PPSA indicates that the dopant anions are bound in two energetically different sites. In the so-called "binding site", the ClO4- anion is Coulombically attracted to the positively charged S or N sites on one chain and simultaneously hydrogen-bonded with the N-H group on a neighboring polymer chain. This strong interaction causes a re-organization of the polymer chains, resulting in the formation of a networked structure linked together by these ClO4- Coulombic/hydrogen bonding "bridges". However, in the "non-binding site", the ClO4- anion is very weakly bound, involves only the electrostatic interaction and can be reversibly exchanged when the doped polymer is reduced. In the repeated cycling, the continuous an...

Physico-chemical factors conditioning the electronic conduction of conductive polymers

2021

The driving idea and the main objective of this synthetic work is the study of physicochemical factors such as the dielectric constant of the solvent, the polarizability of the chains and the Gap energy of the conductive polymers, these characteristics condition their properties. electrical and electrochemical. We focused our study on polyaniline, two synthetic methods are presented: chemical polymerization and electropolymerization with emphasis on the theoretical aspects of the phenomena involved as well as on the electrochemical methods used such as cyclic voltammetry. We have therefore developed with maximum clarity the links existing between the physico-chemical properties of polyaniline and its electrical conductivity.

The semiconducting state of conjugated polymers

arXiv: Mesoscale and Nanoscale Physics, 2019

Recently a variety of pi-conjugated polymers have been developed and essayed for a number of applications such as organic light--emitting diodes (OLEDs), organic field-effect transistors (OFETs), organic photovoltaics (OPVs), and sensors. Some of them are now in mass production. Is central for these applications the semiconductor character of the pure materials, which can turn into metallic conductivity by local oxydation or reduction. The issue is that pi\pipi--electrons are paired in covalent highly localized stable orbitals and interact strongly between them and with the ionic cores, thus being far from the extended quasi--free independent electron states assumed by the theory of inorganic semiconductors. A model yielding a mechanism for many--body conduction of charge and semiconducting properties of the undoped material is introduced here.