Trapping and recombination phenomena in different conformations of irradiated P(VDF/TrFE) copolymer

In this work we show that radiation induced localized levels (trapping effects) and conductivity (RIC) phenomena in poly(vinylidene fluoride)-trifluoroethylene P(VDF-TrFE) copolymer samples depends on the molecular conformation. It was observed that at room temperature, under which P(VDF-TrFE) is ferroelectric and possesses a trans-planar conformation, recombination of charge carriers is negligible. Above the Curie temperature (TGTG´ conformation), the RIC is three orders of magnitude higher, and recombination becomes an important process as the trapping time is considerably reduced. The experimental results were analysed using a modified multiple-trapping model usually applied to disordered materials. Important charge transport parameters were determined for the P(VDF-TrFE) copolymer for both, its ferro- and paraelectric phases