Preparing and polarizing stability of Teflon AF nonlinear optical polymer electret double layer film system

Nonlinear optical activity of an nonlinear optical (NLO) polymer electret originates from the preferential orientation of dipoles doped or chemically attached to the polymer matrix. In this paper, the idea of fabricating a Teflon AF/nonlinear optical polymer electret double layer film system is proposed to improve the orientation stability of the dipole in the polymer electret. The polar stability has been investigated by means of measuring the open-circuit thermally stimulated depolarization (TSD) spectrum, the electro-optical coefficient, and the isothermal surface potential decay. The results indicate that the double layer film system may markedly increase the orientation stability of the dipole in the NLO polymer layer. Because the Teflon AF layer has high charge storage stability, the dipole orientation can be bound by the electric field generated by the space charge in Teflon AF layer.