Ferroelectric switching studies in symmetric Ag/Poly(vinylidene fluoride-co-hexafluoropropylene)/Ag capacitor structures

摘要

In this article, ferroelectric switching properties of Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDFHFP) thin films across symmetric Ag/PVDF-HFP/Ag capacitor structures have been investigated. The structural, microstructural and optical properties of the films are evaluated with grazing incidence X-ray diffraction, Atomic Force Microscopy, and UV visible spectrophotometer. Symmetric quasi-static current-voltage loops exhibit ferroelectric switching, and the corresponding electric displacement- electric field loops show an increase in the coercive field, with the increase in the amplitude of the applied electric field. Higher resistivity of (1.66 - 5.16) x 108 omega;-cm along with optical band gap of 4 eV indicated the good quality of the junctions. Dynamic Polarization-Electric field loops reveal a remnant polarization of 3.22 mu;C/cm2 and 3.16 mu;C/cm2 for 80 nm and 160 nm PVDF-HFP films. The increase in coercive field, remnant and saturation polarization parameters with rise in the amplitude of the applied electric fields at 1 Hz for 160 nm PVDF-HFP film are linked to the uniform domain growth phenomena.