Speaker
Description
P(VDF-TrFE) copolymers actually have a variety of potential applications, e.g. volatile memory, flexible electronics, artificial skin. Anisotropy of their ferroelectric phases make them interesting for optics, from the reasons of polarimetrical phase containment control and potential optoelectronic applications.
Two samples were been fabricated. They are polymer films enclosed between two silver electrodesю Polymer was deposited by spincoating P(VDF-TrFE) 75:25 15% and 17% solutions in DMA, silver – by thermal evaporation.
Then the samples were annealed at 140 °C during 4 hours to achieve alpha-phase.
Angular polarimetry of the samples was carried out at wavelength λ = 625 nm. The Stokes vector components of the reflected light were measured with and without DC voltage applied to the electrodes. From the components of the vector one can find the polarization degree of the reflected light, as well as ellipsometric parameters ψ and Δ of the samples.
Application of 10 V caused changes in both of ψ and Δ parameters up to 1 °. As for the sample of 17%, with the voltage applied we have qualitative changes in the angular dependence ψ - it forms a gap of about 3 ° in depth, the position of which differs for different voltage values. This may be due to interference effects in the piezoelectric three-layer structure (remember that the 17% polymer film turned out to be more perfect), but the final clarification of this issue requires further research. No regular changes in the graph Δ are noticeable for the samples.
