Transport properties of chemically synthesized polypyrrole thin films

TL;DR

This study investigates the electronic transport properties of chemically synthesized polypyrrole thin films, revealing unique temperature and field-dependent behaviors distinct from other forms, with implications for their use in electronic devices.

Contribution

It provides new insights into the transport mechanisms of vapor-phase synthesized polypyrrole films, highlighting differences from electrochemically grown and bulk films.

Findings

Transition from Efros-Shklovskii to Arrhenius behavior at 30 K

High electric fields induce short-range hopping

Magnetoresistance is field-dependent below a critical magnetic field

Abstract

The electronic transport in polypyrrole thin films synthesized chemically from the vapor phase is studied as a function of temperature as well as of electric and magnetic fields. We find distinct differences in comparison to the behavior of both polypyrrole films prepared by electrochemical growth as well as of the bulk films obtained from conventional chemical synthesis. For small electric fields F, a transition from Efros-Shklovskii variable range hopping to Arrhenius activated transport is observed at 30 K. High electric fields induce short range hopping. The characteristic hopping distance is found to be proportional to F^(-1/2). The magnetoresistance R(B) is independent of F below a critical magnetic field, above which F counteracts the magnetic field induced localization.