Influence of annealing on dielectric and polarization behavior of PVDF thick films

Abstract

The polyvinylidene fluoride (PVDF) thick film has been fabricated by a solution casting method. The fabricated film is subjected to annealing at 50, 90, 100, 110 and 130 °C for 5 h. The effect of annealing on structural, crystalline, dielectric and polarization behavior is investigated. The β-phase PVDF is found to coexist with α-phase for annealing temperature upto 100 °C, after that β-phase is converted to α-phase. The film annealed at 100 °C, exhibits enhanced permittivity, reduced tangent loss and enhanced polarization. The dielectric permittivity and tangent loss of film annealed at 100 °C are ~11 and ~0.025 respectively for the frequency range of 103–105 Hz. The saturation polarization for this film is ~1.27 µC/cm2. The enhanced dielectric permittivity and polarization for the film annealed at 100 °C might be attributed to increase in crystalline α and β-phase interface as well as crystalline amorphous interface. The thick film of PVDF with improved dielectric and polarization behavior could be useful for high power electronics application.