Effect of various annealing temperature on the morphological and dielectric properties of Polyvinylidenefluoride-Trifluoroethylene thin film

The morphology of PVDF-TrFE (70/30) thin film at various annealing temperature were investigated using non-contact mode Atomic Force Microscopy (AFM). Differential Scanning Calorimetry (DSC) technique was used to obtain T_C, T_m, and T_Crys of PVDF-TrFE. The prepared spin coated PVDF-TrFE (70/30) thin films were annealed at T_C (113°C), T_m (154°C), T_Crys (135°C) and T_c at cooling (55°C) in accordance to the DSC thermogram observed. Impedance Spectroscopy were conducted to study the dielectric characteristic of the thin films in order to substantiate the electrical behavior of the thin films From the results obtained, the thin films exhibited different morphologies depending on the annealing temperatures utilized. Formation of needle-like crsytallite structure was observed film annealed at and over T_m. Thin film re-crystallized at T_C has an optimized dielectric constant of ~7.8 at 10⁴ hz.