Effect of Annealing Temperature on the Crystallinity, Morphology and Ferroelectric of Polyvinylidenefluoride-Trifluoroethylene (PVDF-TrFE) Thin Film

Abstract

The annealing temperature for 250 nm PVDF-TrFE (70:30 mol %) spin coated thin films were varied at solvent evaporation (T s = 79 ˚C), Curie's transition (T c = 113 ˚C) , till melting temperature (T m = 154 ˚C). XRD measurement showed that, there was an improvement in the crystallinity of the annealed films, consistent with the increased in the annealing temperatures. Morphological studies of the annealed PVDF-TrFE thin films as observed with Field Emission Scanning Electron Microscope (FESEM) (100k magnification), showed enhanced development of elongated crystallite structures known as ferroelectric crystal. However, thin film annealed at 160 ˚C (AN160) showed fibrous-like structure with appearance of nanoscale separations, which suggested high possibility of defects. Ferroelectric characterization indicated an improvement in the remnant polarization of annealed PVDF-TrFE thin films with the exception to AN160 in which leakage of current was inevitable due to the presence of cracks on the film surface.

Solvent-Dependent Electrical Characteristics and Mechanical Stability of Flexible Organic Ferroelectric Field-Effect Transistors

“…In P(VDF-TrFE) films from DMF and MEK solvents, XRD peaks were observed at 20.05° and 19.97°, respectively, corresponding to the typical range of the β-phase. This indicates that both films have suitable dielectric and ferroelectric properties for the insulation of Fe-FETs by virtue of a switchable dipole moment from β-phase crystal structure [22,23]. Boiling point is one of the most influential factors that affect morphology, crystallinity, and electrical characteristics of organic semiconductors [24,25].…”

Limiting Relative Permittivity “Burn-in” in Polymer Ferroelectrics via Phase Stabilization

“…Our strategy is expected to be broadly applicable to other VDF-based materials as it relies on general polymers physics frameworks. This strategy is also superior compared to approaches frequently used in literature that employ post-film-deposition treatments such as thermal annealing. , This is highlighted in Figure S4. We like to note, however, that likely compromises will need to be sought with respect to N , M , and solvent evaporation rate to induce a desired materials property set.…”