On the role of charge injection and trapping in stability of polarization in ferroelectric polymers

The 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 a deep trapping of the charge carriers during the polarization buildup in ferroelectric polymers. The model calculations are made on a distribution of the potential energy at the surface of the polarized crystallites, proving that additional sites for the charge trapping are created there. It Is shown how to provide the most favourable conditions for obtaining a stable polarization in ferroelectric polymers.