Effect of electric field assisted crystallisation of PVDF-TrFE and their functional properties

Uniform thin films of poly(vinylidene fluoride)-trifluoroethylene copolymers were spin-coated and their functional electrical properties were investigated after corona poling. The copolymers were poled in the gel state at room temperature (RT) without stretching or annealing treatment. This E-field crystallisation processing method at RT leads to the formation of improved ferroelectric and pyroelectric properties in the investigated thin films. That processing method has great potential for ferroelectric material coatings on thermally highly sensitive substrates. The selected composition (similar to 1 mu m thick composites of 65/35 mol% PVDF-TrFE) of the copolymer produced a pyroelectric coefficient value of 36 +/- 3 mu C/m(2)K(1), a dielectric constant of 9, and a dielectric loss of about 0.018 at a frequency of 1 kHz under ambient conditions. (C) 2021 Elsevier B.V. All rights reserved.