Origin of absorption and resorption currents in the co-polymer poly(hexafluoropropylene-tetrafluoroethylene)

Abstract

A range of experimental evidence is presented showing that absorption and resorption currents in 125 mu m thick samples of the co-polymer(hexafluoropropylene-tetrafluoroethylene) are dominated by lateral charge transfer between the edge of the evaporated aluminium electrode and the surrounding uncoated polymer surface, rather than by bulk conductivity processes. These currents were found to increase proportionally with the electrode perimeter, rather than with the electrode area as would be expected if bulk conductivity processes were dominant. The surface conductivity mechanism accounts for at least 90% of the charge under the current-time plots.