Molecular orientation of polar organic vacuum-deposited films and effect of electric field during deposition

Abstract

Thin films of (VDF/TrFE) copolymer were prepared by a vacuum deposition method under an electric field. Particularly, the molecular orientation was controlled to obtain the films with uniaxial dipole orientation. Also, to get the films with much higher crystallinity, a newly synthesized VDF telomer, low molecular weight sample of PVDF, was used as a deposition source. Here, the evaluation of the crystal structure and molecular orientation in the vacuum deposited films were conducted by means of a recently developed total reflection X-ray difftactometer and FT-IR. The results revealed that the films form the crystals similar to form II of PVDF and the molecular orientation is normal to the substrate. Moreover, it was revealed that the molecular orientation changes from normal to parallel to the substrate at the substrate temperature below - 30 °C.