Charge Trapping in Ferroelectric Polymers

TL;DR

This paper investigates charge trapping phenomena in ferroelectric polymers, specifically PVDF, revealing deep trap states during polarization buildup and modeling their effects on surface potential energy distribution.

Contribution

It provides experimental evidence and a theoretical model for deep charge trapping in ferroelectric polymers during polarization.

Findings

Absorption currents show anomalous behavior during voltage increase.

Deep charge traps are created at crystallite surfaces.

Model confirms additional trapping sites at polarized crystallites.

Abstract

Experimental results are presented on anomalous behavior of absorption currents in PVDF during the stepwise increase of the voltage applied through a corona. These results, supplemented with the dynamics of the time constant of the electret potential decay are consistent with a hypothesis assuming deep trapping of the charge carriers during the polarization buildup in ferroelectric polymers. Model calculations are made on distribution of the potential energy at the surface of the polarized crystallites proving that additional sites for the charge trapping are created there.