Optimization of Annealing Temperature for PVDF-TrFE (70:30 mol %) Thin Film

Abstract

The annealing temperature of 250nm PVDF-TrFE (70:30 mol%) spin coated thin films were optimized. The annealing temperature were varies starting from solvent evaporation (T s ), Curie's transition (T c ), up to melting temperature (T m ). The result shows that the dielectric constant increases with the increasing of annealing temperature. Supported with the XRD observation indicating there were an improvement in crystallinity consistently with the increasing of the annealing temperature. Morphological properties of the annealed PVDF-TrFE thin films were observed by utilizing Field Emission Scanning Electron Microscope (FESEM) at 100k magnification. It can be found that, the annealing temperature promotes the development of elongated crystallite structure which known as ferroelectric crystal. However, the presence of nanoscale cracks on the thin film annealed at 160˚C (AN160, over T m ) suggesting high possibility to posed defects while in device applications.

Ultrathin Epidermal P(VDF-TrFE) Piezoelectric Film for Wearable Electronics

“…33 The annealing is a common method used to optimize the crystallinity of the PVDF-based polymer and is therefore employed to modulate the piezoelectricity of the prepared ultrathin film. 34 According to the Curie temperature (T c ≈ 105 °C) and the melting temperature (T m ≈ 150 °C) of P(VDF-TrFE), 31 a series of annealing temperatures (T a ) between 90 and 170 °C were selected to treat the films (the process was described in Experimental Section). As presented in Figure 2d−f and Supporting Information Figure S1, the size and density of ferroelectric crystals were increasing continuously while the T a was below 130 °C, which could be ascribed to the enhanced movement of polymer chains as increasing temperature.…”

“…For the PVDF-based piezoelectric polymer, just the all-trans ferroelectric β conformation in the crystal region could form the microscopic dipole moment and generate piezoelectricity . The annealing is a common method used to optimize the crystallinity of the PVDF-based polymer and is therefore employed to modulate the piezoelectricity of the prepared ultrathin film . According to the Curie temperature ( T c ≈ 105 °C) and the melting temperature ( T m ≈ 150 °C) of P­(VDF-TrFE), a series of annealing temperatures ( T a ) between 90 and 170 °C were selected to treat the films (the process was described in Experimental Section).…”