Enhanced performance of ferroelectric-based all organic capacitors and transistors through choice of solvent

Abstract

We examine the role of solvents in the performance of pentacene devices using the ferroelectric copolymer poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFe) as a gate insulating layer. High dipole moment solvents, such as dimethyl sulfoxide (DMSO), used to dissolve the copolymer for spincasting, increase the charge carrier mobility in field-effect transistors by nearly an order of magnitude as compared to lower dipole moment solvents. The polarization in Al/PVDF-TrFe/Au metal-ferroelectric-metal devices is also investigated. An increase in remnant polarization of ∼20% is observed in the sample using DMSO as the ferroelectric solvent. The DMSO based sample shows a hysteresis in its displacement curve even at the lowest measured voltage, indicating that the dipoles in the copolymer are more ordered initially.