Crystallization mechanism and piezoelectric properties of solution-derived ferroelectric poly(vinylidene fluoride) thin films

beta-phase dominant poly(vinylidene fluoride) (PVDF) ferroelectric thin films were obtained on silicon substrates by spin coating the precursor solutions with addition of hydrate salt and drying at an elevated temperature. The remnant polarization of the dense beta-phase dominant PVDF thin film was 69.5 mC/m(2). The apparent longitudinal piezoelectric coefficient d(33) was -17.4 pm/V without taking into account the substrate clamping effect. It was suggested that the hydrate salt functioned as nucleation sites for the crystallization of PVDF molecules, and the intermolecular hydrogen bonding together with dipolar interactions promoted all-trans conformation and beta-phase formation. (c) 2006 American Institute of Physics.